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The Home Medical
Library
By
KENELM WINSLOW, B.A.S., M.D.
_Formerly Assistant Professor Comparative Therapeutics, Harvard
University; Late Surgeon to the Newton Hospital;
Fellow of the Massachusetts Medical Society, etc._
With the Cooperation of Many Medical
Advising Editors and Special Contributors
IN SIX VOLUMES
_First Aid :: Family Medicines :: Nose, Throat, Lungs,
Eye, and Ear :: Stomach and Bowels :: Tumors and
Skin Diseases :: Rheumatism :: Germ Diseases
Nervous Diseases :: Insanity :: Sexual Hygiene
Woman and Child :: Heart, Blood, and Digestion
Personal Hygiene :: Indoor Exercise
Diet and Conduct for Long Life :: Practical
Kitchen Science :: Nervousness
and Outdoor Life :: Nurse and Patient
Camping Comfort :: Sanitation
of the Household :: Pure
Water Supply :: Pure Food
Stable and Kennel_
NEW YORK
The Review of Reviews Company
1907
Medical Advising Editors
Managing Editor
ALBERT WARREN FERRIS, A.M., M.D.
_Former Assistant in Neurology, Columbia University; Former Chairman,
Section on Neurology and Psychiatry, New York Academy of Medicine;
Assistant in Medicine, University and Bellevue Hospital Medical
College; Medical Editor, New International Encyclopedia._
Nervous Diseases
CHARLES E. ATWOOD, M.D.
_Assistant in Neurology, Columbia University; Former Physician, Utica
State Hospital and Bloomingdale Hospital for Insane Patients; Former
Clinical Assistant to Sir William Gowers, National Hospital, London._
Pregnancy
RUSSELL BELLAMY, M.D.
_Assistant in Obstetrics and Gynecology, Cornell University Medical
College Dispensary; Captain and Assistant Surgeon (in charge),
Squadron A, New York Cavalry; Assistant in Surgery, New York
Polyclinic._
Germ Diseases
HERMANN MICHAEL BIGGS, M.D.
_General Medical Officer and Director of Bacteriological Laboratories,
New York City Department of Health; Professor of Clinical Medicine in
University and Bellevue Hospital Medical College; Visiting Physician
to Bellevue, St. Vincent's, Willard Parker, and Riverside Hospitals._
The Eye and Ear
J. HERBERT CLAIBORNE, M.D.
_Clinical Instructor in Ophthalmology, Cornell University Medical
College; Former Adjunct Professor of Ophthalmology, New York
Polyclinic; Former Instructor in Ophthalmology in Columbia University;
Surgeon, New Amsterdam Eye and Ear Hospital._
Sanitation
THOMAS DARLINGTON, M.D.
_Health Commissioner of New York City; Former President Medical Board,
New York Foundling Hospital; Consulting Physician, French Hospital;
Attending Physician, St. John's Riverside Hospital, Yonkers; Surgeon
to New Croton Aqueduct and other Public Works, to Copper Queen
Consolidated Mining Company of Arizona, and Arizona and Southeastern
Railroad Hospital; Author of Medical and Climatological Works._
Menstruation
AUSTIN FLINT, JR., M.D.
_Professor of Obstetrics and Clinical Gynecology, New York University
and Bellevue Hospital Medical College; Visiting Physician, Bellevue
Hospital; Consulting Obstetrician, New York Maternity Hospital;
Attending Physician, Hospital for Ruptured and Crippled, Manhattan
Maternity and Emergency Hospitals._
Heart and Blood
JOHN BESSNER HUBER, A.M., M.D.
_Assistant in Medicine, University and Bellevue Hospital Medical
College; Visiting Physician to St. Joseph's Home for Consumptives;
Author of "Consumption: Its Relation to Man and His Civilization; Its
Prevention and Cure."_
Skin Diseases
JAMES C. JOHNSTON, A.B., M.D.
_Instructor in Pathology and Chief of Clinic, Department of
Dermatology, Cornell University Medical College._
Diseases of Children
CHARLES GILMORE KERLEY, M.D.
_Professor of Pediatrics, New York Polyclinic Medical School and
Hospital; Attending Physician, New York Infant Asylum, Children's
Department of Sydenham Hospital, and Babies' Hospital, N. Y.;
Consulting Physician, Home for Crippled Children._
Bites and Stings
GEORGE GIBIER RAMBAUD, M.D.
_President, New York Pasteur Institute._
Headache
ALONZO D. ROCKWELL, A.M., M.D.
_Former Professor Electro-Therapeutics and Neurology at New York
Post-Graduate Medical School; Neurologist and Electro-Therapeutist to
the Flushing Hospital; Former Electro-Therapeutist to the Woman's
Hospital in the State of New York; Author of Works on Medical and
Surgical Uses of Electricity, Nervous Exhaustion (Neurasthenia), etc._
Poisons
E. ELLSWORTH SMITH, M.D.
_Pathologist, St. John's Hospital, Yonkers; Somerset Hospital,
Somerville, N. J.; Trinity Hospital, St. Bartholomew's Clinic, and the
New York West Side German Dispensary._
Catarrh
SAMUEL WOOD THURBER, M.D.
_Chief of Clinic and Instructor in Laryngology, Columbia University;
Laryngologist to the Orphan's Home and Hospital._
Care of Infants
HERBERT B. WILCOX, M.D.
_Assistant in Diseases of Children, Columbia University._
Special Contributors
Food Adulteration
S. JOSEPHINE BAKER, M.D.
_Medical Inspector, New York City Department of Health._
Pure Water Supply
WILLIAM PAUL GERHARD, C.E.
_Consulting Engineer for Sanitary Works; Member of American Public
Health Association; Member, American Society Mechanical Engineers;
Corresponding Member of American Institute of Architects, etc.; Author
of "House Drainage," etc._
Care of Food
JANET MCKENZIE HILL
_Editor, Boston Cooking School Magazine._
Nerves and Outdoor Life
S. WEIR MITCHELL, M.D., LL.D.
_LL.D. (Harvard, Edinburgh, Princeton); Former President, Philadelphia
College of Physicians; Member, National Academy of Sciences,
Association of American Physicians, etc.; Author of essays: "Injuries
to Nerves," "Doctor and Patient," "Fat and Blood," etc.; of scientific
works: "Researches Upon the Venom of the Rattlesnake," etc.; of
novels: "Hugh Wynne," "Characteristics," "Constance Trescott," "The
Adventures of Francois," etc._
Sanitation
GEORGE M. PRICE, M.D.
_Former Medical Sanitary Inspector, Department of Health, New York
City; Inspector, New York Sanitary Aid Society of the 10th Ward, 1885;
Manager, Model Tenement-houses of the New York Tenement-house Building
Co., 1888; Inspector, New York State Tenement-house Commission, 1895;
Author of "Tenement-house Inspection," "Handbook on Sanitation," etc._
Indoor Exercise
DUDLEY ALLEN SARGENT, M.D.
_Director of Hemenway Gymnasium, Harvard University; Former President,
American Physical Culture Society; Director, Normal School of Physical
Training, Cambridge, Mass.; President, American Association for
Promotion of Physical Education; Author of "Universal Test for
Strength," "Health, Strength and Power," etc._
Long Life
SIR HENRY THOMPSON, Bart., F.R.C.S., M.B. (Lond.)
_Surgeon Extraordinary to His Majesty the King of the Belgians;
Consulting Surgeon to University College Hospital, London; Emeritus
Professor of Clinical Surgery to University College, London, etc._
Camp Comfort
STEWART EDWARD WHITE
_Author of "The Forest," "The Mountains," "The Silent Places," "The
Blazed Trail," etc._
[Illustration: WALTER REED.
In the year 1900, Major Walter Reed, a surgeon in the United States
Army, demonstrated, by experiments conducted in Cuba, that a mosquito
of a single species, Stegomyia fasciata, which has sucked the blood of
a yellow-fever patient may transmit the disease by biting another
person, but not until about twelve days have elapsed. He also proved,
as described in Volume I, Part II, that the malady is not contagious.
"With the exception of the discovery of anaesthesia," said Professor
Welch, of Johns Hopkins University, "Dr. Reed's researches are the
most valuable contributions to science ever made in this country."
General Leonard Wood declared the discovery to be the "greatest
medical work of modern times," which, in the words of President
Roosevelt, "renders mankind his debtor." Major Reed died November 23,
1902.]
The Home Medical
Library
VOLUME V :: SANITATION
Edited by
THOMAS DARLINGTON, M.D.
_Health Commissioner of New York City; Former President Medical Board,
New York Foundling Hospital, etc.; Author of Medical and
Climatological Works_
WATER SUPPLY AND PURIFICATION
By WILLIAM PAUL GERHARD, C.E.
_Consulting Engineer for Sanitary Works; Author of "House Drainage,"
"Sanitary Engineering," "Household Wastes," etc._
PURE FOOD FOR THE
HOUSEKEEPER
By S. JOSEPHINE BAKER, M.D.
_Medical Inspector, New York City Department of Health_
THE HOUSE AND GROUNDS
By GEORGE M. PRICE, M.D.
_Former Medical Sanitary Inspector, Department of Health, New York
City; Author of "Tenement-House Inspection," "Handbook on Sanitation,"
etc._
NEW YORK
The Review of Reviews Company
1907
Copyright, 1907, by
THE REVIEW OF REVIEWS COMPANY
THE TROW PRESS, NEW YORK
_Contents_
PART I
CHAPTER PAGE
I. COUNTRY SOURCES OF WATER SUPPLY 19
Relation of Water to Health--Collection of Rain
Water--Cisterns--Springs--Various Kinds of
Wells--Laws Regulating Supply.
II. APPLIANCES FOR DISTRIBUTING WATER 39
Pumping Machines--The Hydraulic Ram--Use of
Windmills--Engines--Steam and Electric
Pumps--Reservoirs and Tanks--Appliances for Country
Houses.
III. PURIFYING WATER BY COPPER SULPHATE 52
Clear Water Often Dangerous--Pollution Due to
Plants--Copper Sulphate Method--Directions for the
Copper Cure.
IV. RIDDING STAGNANT WATER OF MOSQUITOES 70
Malaria Due to Mosquitoes--Cause of Yellow
Fever--Effect of a Mosquito Bite--Destruction of
Larvae--Best Preventive Measures--Use of Kerosene.
PART II
I. HOW TO DETECT FOOD ADULTERATION 87
Definition of Adulteration--Food Laws--Permissible
Adulterants--How to Select Pure Food--Chemical
Tests.
II. MUSHROOM POISONING 112
Symptoms and Treatment--Coffee and Atropine the Best
Antidotes--How to Tell the Edible Kind--"Horse,"
"Fairy-ring," and Other Varieties--Poisonous
Species.
PART III
I. SOIL AND SITES 131
Constituents of the Soil--Influence on
Health--Improving Defective Soil--Street Paving and
Tree Planting--Proper Construction of
Houses--Subsoil Drainage.
II. VENTILATION 146
What is Meant by Ventilation--Quantity of Air
Required--Natural Agents of Ventilation--Special
Appliances.
III. WARMING 160
Various Methods--Materials of
Combustion--Chimneys--Fireplaces and
Grates--Stoves--Hot-air Warming--Hot-water
Systems--Principles of Steam Heating.
IV. DISPOSAL OF SEWAGE 170
Refuse and Garbage--Discharge into
Waters--Cremation--Precipitation--Intermittent
Filtration--Immediate Disposal, etc.
V. SEWERS 182
Definition--Materials Used in Construction--Levels
of Trenches--Joints of Pipes--The Fall and Flow of
the Contents--Connections--Tide Valves--Sewer Gas.
VI. PLUMBING 189
Purposes and Requisites--Materials Used--Joints and
Connections--Construction of Traps--Siphonage and
Back Pressure--The Vent-pipe System.
VII. PLUMBING PIPES 206
Construction of House Drains--Fall, Position, and
Connection--Main Traps--Extension of Vertical
Pipes--Fresh-air Inlets--Soil and Waste
Pipes--Branch Pipes, etc.
VIII. PLUMBING FIXTURES 216
Sinks--Washbasins--Washtubs--Bathtubs--Refrigerators,
etc.--Safes and Wastes--Pan, Valve, and Hopper
Closets--Flush Tanks--Yard Closets--Drains.
IX. DEFECTS IN PLUMBING 231
Poor Work--Improper Conditions--How to Test Traps,
Joints, and Connections--Detect Sewer
Gas--Water-pressure, Smoke, and Scent Tests--Special
Appliances.
X. INFECTION AND DISINFECTION 238
Physical and Chemical Disinfectants--Use of Sulphur
Dioxide--Formaldehyde--Hydrocyanic
Acid--Chlorine--Carbolic Acid--Bichloride of
Mercury--Formalin--Potassium Permanganate, etc.
XI. COST OF CONVEYED HEATING SYSTEMS 254
Cost of Hot-air Systems--Cast-iron Hot-water
Heater--Advantages and Disadvantages--Cost for a
Ten-room House--Steam Heating--Cost of Equipment.
_The Editor's Preface_
The character and scope of this volume render it a most useful book
for the home maker. The question of sanitation is one that closely
affects the life of each individual, and many of its aspects are
treated here in a lucid and comprehensive manner. Designed for wide
distribution, these articles have been written to meet the needs of
the dweller in the more densely populated communities, as well as
those living in the less thickly settled portion of the country.
In large cities the water supply is a problem that is cared for by
regularly constituted sanitary authorities. Pure water is a vital
necessity, but the inhabitant of a city has no need to personally
concern himself with the source of supply. In the country, however,
the home builder must often decide the matter for himself, and it is
the aim of this book to give him the needed directions for avoiding
many errors and pitfalls that abound in this direction.
House construction, with its intricate problems, is also a more
serious matter for the country dweller than for his city brother.
In the matter of food supply, the inhabitant of a country district is
more fortunate. Fresh vegetables and dairy products are much more
easily obtained, and their freshness and purity more dependable.
The article on water supply by Mr. Gerhard is authoritative, written,
as it is, by a most eminent sanitarian. The publishers are to be
congratulated upon the following valuable contribution to the same
subject as regards the use of copper sulphate and the concise
presentation of plans for mosquito extermination, while the extended
work of Dr. Price and Dr. Baker's "Food Adulteration" are much to be
commended. The two latter have been connected with the Department of
Health of New York City, and have the advantage of experience in an
organization which gives to the citizens of New York the protection to
health that the wise use of science, knowledge, and money afford.
I trust that the notes I have added in the light of recent practice of
the New York City Department of Health may make this material of the
utmost practical value to the householder of to-day.
Through this Department of Health, New York City spent, during 1905,
over $1,500,000, and for 1906 it has appropriated over $1,800,000.
This vast sum of money is used for the sole purpose of safeguarding
its citizens from disease. Sanitation in its varied branches is
pursued as an almost exact science, and the efforts of trained minds
are constantly employed in combating disease and promoting sanitation.
The cities care for their own, but the greater number of the
inhabitants of this country must rely upon their individual efforts.
Therefore, any dissemination of knowledge regarding sanitation is most
worthy. This book has a useful mission. It is pregnant with helpful
suggestions, and I most heartily commend its purpose and its contents.
THOMAS DARLINGTON,
_President of the Board of Health_.
NEW YORK CITY.
Part I
WATER SUPPLY AND
PURIFICATION
BY
WILLIAM PAUL GERHARD
CHAPTER I
=Country Sources of Water Supply=
The writer was recently engaged to plan and install a water-supply
system for a country house which had been erected and completed
without any provision whatever having been made for supplying the
buildings and grounds with water. The house had all the usual
appointments for comfort and ample modern conveniences, but these
could be used only with water borrowed from a neighbor. In all parts
of the country there are numerous farm buildings which are without a
proper water-supply installation. These facts are mentioned to
emphasize the importance of a good water supply for the country home,
and to point out that water is unquestionably the most indispensable
requirement for such structures.
_Adequate Water Supply Important_
But the advantages of a water supply are not limited to the dwelling
house, for it is equally useful on the farm, for irrigation, and in
the garden, on the golf grounds and tennis courts, in the barns and
stables; it affords, besides, the best means for the much-desired
fire protection. And, most important of all, an unstinted and adequate
use of water promotes cleanliness and thereby furthers the cause of
sanitation, in the country not less than in the city home.
The water supply for country houses has been so often discussed
recently that the writer cannot hope to bring up any new points. This
article should, therefore, be understood to offer simple suggestions
as to how and where water can be obtained, what water is pure and fit
for use, what water must be considered with suspicion, what water is
dangerous to health, and how a source of supply, meeting the
requirements of health, can be made available for convenient use.
Right here I wish to utter a warning against the frequent tendency of
owners of country houses to play the role of amateur engineers. As a
rule this leads to failure and disappointment. Much money uselessly
spent can be saved if owners will, from the beginning, place the
matter in experienced hands, or at least seek the advice of competent
engineers, and adopt their suggestions and recommendations as a guide.
_Points to be Borne in Mind_
Many are the points to be borne in mind in the search for water.
Science teaches us that all water comes from the clouds, the
atmospheric precipitation being in the form of either rain, or dew, or
snow. After reaching the earth's surface, the water takes three
different courses, and these are mentioned here because they serve to
explain the different sources of supply and their varied character.
A part of the water runs off on the surface, forming brooks, streams,
and lakes, and if it falls on roofs of houses or on prepared catchment
areas, it can be collected in cisterns or tanks as rain water. Another
part of the water soaks away into pervious strata of the subsoil, and
constitutes underground water, which becomes available for supply
either in springs or in wells. A third part is either absorbed by
plants or else evaporated.
In our search for a source of supply, we should always bear in mind
the essential requirements of the problem. Briefly stated, these are:
the wholesomeness of the water, the adequateness and steadiness of the
supply, its availability under a sufficient pressure, insuring a good
flow, and the legal restrictions with which many water-supply problems
are surrounded.
The first essential requirement is that of _wholesomeness_. The
quality of a water supply is dependent upon physical properties and
upon chemical and bacteriological characteristics. Water, to be
suitable for drinking, must be neither too hard nor too soft; it
should not contain too many suspended impurities, nor too much foreign
matter in solution. Pure water is colorless and without odor. But it
must be understood that the quality cannot be decided merely by the
color, appearance, taste, and odor. The chemical and bacteriological
examinations, if taken together, form a much safer guide, and with
these analyses should go hand in hand a detailed survey of the water
source and its surroundings.
_Relation of Water to Health_
Any pronounced taste in the water renders it suspicious; an offensive
smell points to organic contamination; turbidity indicates presence of
suspended impurities, which may be either mineral or organic. But even
bright and sparkling waters having a very good taste are sometimes
found to be highly polluted. Hence, it should be remembered that
neither bright appearance nor lack of bad taste warrants the belief
that water is free from dangerous contamination.
It is a well-established fact now that there is a relation between the
character of the water supply and the health of a community; and what
is true of cities, villages, and towns, is, of course, equally true of
the individual country house.
_How Water Becomes Contaminated_
There are numerous ways in which water may become polluted, either at
the source or during storage or finally during distribution. Rain
water, falling pure from the clouds, encounters dust, soot, decaying
leaves and other vegetable matters, and ordure of birds on the roofs;
its quality is also affected by the roofing material, or else it is
contaminated in the cisterns by leakage from drains or cesspools.
Upland waters contain generally vegetable matter, while surface water
from cultivated lands becomes polluted by animal manure. River water
becomes befouled by the discharge into it of the sewers from
settlements and towns located on its banks. Subsoil water is liable to
infiltration of solid and liquid wastes emanating from the human
system, from leaky drains, sewers, or cesspools, stables, or
farmyards; and even deep well water may become contaminated by reason
of defects in the construction of the well.
During storage, water becomes contaminated in open reservoirs by
atmospheric impurities; a growth of vegetable organisms or algae often
causes trouble, bad taste, or odor; water in open house tanks and in
cisterns is also liable to pollution. During distribution, water may
become changed in quality, owing to the action of the water on the
material of the pipes.
From what source shall good water be obtained? This is the problem
which confronts many of those who decide to build in the country.
The usual sources, in their relative order of purity, are: deep
springs and land or surface springs, located either above or below the
house, but not too near to settlements; deep subterranean water, made
available by boring or drilling a well; upland or mountain brooks
from uninhabited regions; underground water in places not populated,
reached by a dug or driven well; lake water; rain water; surface water
from cultivated fields; pond and river water; and finally, least
desirable of all, shallow well water in villages or towns. These
various sources of supply will be considered farther on.
_An Ample Volume Necessary_
The second essential requirement is _ample quantity_. The supply must
be one which furnishes an ample volume _at all seasons_ and for all
purposes.
What is a reasonable daily domestic consumption? The answer to this
question necessarily depends upon the character of the building and
the habits and occupation of its inmates. It is a universal experience
that as soon as water is introduced it is used more lavishly, but also
more recklessly and regardless of waste. For personal use, from twenty
to twenty-five gallons per person should prove to be ample per day:
this comprises water for drinking and cooking, for washing clothes,
house and kitchen utensils, personal ablutions, and bathing; but,
taking into account other requirements on the farm or of country
houses, we require at least sixty gallons per capita per diem. To
provide water for the horses, cows, sheep, for carriage washing, for
the garden, for irrigation of the lawn, for fountains, etc., and keep
a suitable reserve in case of fire, the supply should be not less
than 150 gallons per person per day.
_A Good Pressure Required_
The third essential requirement is a _good water pressure_. Where a
suitable source of water is found, it pays to make it conveniently
available, so as to avoid carrying water by hand, which is troublesome
and not conducive to cleanliness. A sufficient pressure is attained by
either storing water at, or lifting it to, a suitable elevation above
the point of consumption. In this respect many farm and country houses
are found to be but very imperfectly supplied. Often the tank is
placed only slightly higher than the second story of the house. As a
result, the water flows sluggishly at the bathroom faucets, and, in
case of fire, no effective fire stream can be thrown. Where a
reservoir is suitably located above the house, the pressure is
sometimes lost by laying pipes too small in diameter to furnish an
ample stream. Elevated tanks should always be placed so high as to
afford a good working pressure in the entire system of pipes. Where a
tower of the required height is objectionable, either on account of
the cost or on account of appearance, pressure tanks may be installed
which have many advantages.
In selecting a source of water supply, the following points should be
borne in mind for guidance: first, the wholesomeness of the water;
next, the cost required to collect, store, and distribute the water;
finally, where a gravity supply is unavailable, the probable operating
expenses of the water system, cost of pumping, etc.
_Collection of Rain Water_
The collection of rain water near extensive manufacturing
establishments is not advisable, except where arrangements are
provided for either filtering or distilling the water. In the country,
rain water is pure and good, if the precaution is observed to allow
the first wash from roofs to run to waste. The rain may be either
caught on the roofs, which must always have a clean surface and clean
gutters, or else on artificially prepared catchment areas. As an
example, I quote: "All about the Bermuda Islands one sees great white
scars on the hill slopes. These are dished spaces, where the soil has
been scraped off and the coral rock exposed and glazed with hard
whitewash. Some of these are a quarter acre in size. They catch and
carry the rainfall to reservoirs, for the wells are few and poor, and
there are no natural springs and no brooks." (Mark Twain, "Some
Rambling Notes of an Idle Excursion.")
After the close of the Boer War the English sent about 7,000 Boer
prisoners of war to Bermuda, where they were encamped on some of the
smaller islands of the group, and the entire water supply for the
encampment was obtained by building artificial catchment areas as
described in the above quotation.
Sometimes, instead of building underground cisterns, rain water is
caught and stored in barrels above ground; if so, these should always
be well covered, not only to avoid pollution, but to prevent the
barrels from becoming mosquito breeders. Cisterns should always be
built with care and made water-tight and impervious. The walls should
be lined with cemented brickwork. In soil consisting of hard pan,
cisterns in some parts of the country are built without brick walls,
the walls of the excavation being simply cemented. I do not approve of
such cheap construction, particularly where the cistern is located
near a privy or cesspool. Pollution of cistern water is often due to
the cracking of the cement lining. Overflows of cisterns should never
be connected with a drain, sewer, or cesspool. Run the overflow into
some surface ditch and provide the mouth with a fine wire screen, to
exclude small animals. It is not recommended to build cisterns in
cellars of houses.
_Quality of Water Obtained from Lakes_
Lakes yield, as a rule, a supply of clear, bright, and soft water.
This is particularly the case with mountain lakes, because they are at
a distance from sources of contamination. The character of the water
depends upon whether the lake is fed by brooks, that is, by the rain
falling upon the watershed, or also by springs. In one case the water
is surface water exclusively; in the other, it is surface and
underground water mixed. The purity also depends upon the depth of
the lake and upon the character of its bottom.
Deep lakes furnish a better supply and clearer water than shallow
ones. The solid matter brought into the lake by the brooks or rivers
which feed it does not remain long in suspension, but soon settles at
the bottom, and in this way some lakes acquire the wonderfully clear
water and the beautiful bluish-green color for which they are far
famed.
_Strong Winds Dangerous on Lakes_
Strong winds or currents at times stir up the mud from the bottom;
hence, in locating the intake, the direction of the prevailing winds
should be considered, if practicable. The suction pipe should always
be placed in deep water, at a depth of at least fifteen to twenty
feet, for here the water is purer and always cooler.
Settlements on the shores of a lake imply danger of sewage
contamination, but the larger the lake, the less is the danger of a
marked or serious pollution, if the houses are scattered and few.
Pools and stagnant ponds are not to be recommended as a source of
supply. In artificially made lakes there is sometimes danger of
vegetable pollution, and trouble with growth of algae. The bottom of
such lakes should always be cleared from all dead vegetation.
Surface water may be obtained from brooks flowing through uninhabited
upland or from mountain streams. Such water is very pure and limpid,
particularly where the stream in its downward course tumbles over
rocks or forms waterfalls. But, even then, the watershed of the stream
should be guarded to prevent subsequent contamination. Larger creeks
or rivers are not desirable as a source of supply, for settlements of
human habitations, hamlets, villages, and even towns are apt to be
located on the banks of the river, which is quite generally
used--wrong as it is--as an outlet for the liquid wastes of the
community, thus becoming in time grossly polluted. Down-stream
neighbors are sure to suffer from a pollution of the stream, which the
law should prevent.
_The Water of Springs_
The water of springs is subterranean, or ground water, which for
geological reasons has found a natural outlet on the surface. We
distinguish two kinds of springs, namely, land or surface springs, and
deep springs. The former furnish water which originally fell as rain
upon a permeable stratum of sand or gravel, underlaid by an impervious
one of either clay or rock. Such water soaks away underground until it
meets some obstacle causing it to crop out on the surface. Such spring
water is not under pressure and therefore cannot again rise. Water
from deep springs is rain water fallen on the surface of a porous
stratum on a high level, and which passes under an impermeable
stratum, and thus, being under pressure, rises again where an opening
is encountered in the impervious stratum; these latter springs are
really artesian in character.
Deep-spring water is less apt to be polluted than water from surface
or land springs, for it has a chance in its flow through the veins of
the earth to become filtered. Land springs always require careful
watching, particularly in inhabited regions, to prevent surface
contamination.
_Not all Spring Water Pure_
It is a popular fallacy that all spring water is absolutely pure and
healthful. The above explanation will be helpful in pointing out how,
in some cases, spring water may be nothing but contaminated ground
water. Land springs in uncultivated and uninhabited regions,
particularly in the mountains, yield a good and pure supply. But it is
always advisable, when tapping a spring for water supply, to study its
probable source, and carefully to inspect its immediate surroundings.
The spring should be protected by constructing a small basin, or
reservoir, and by building a house over this. The basin will also
serve to store the night flow of the spring. Before deciding upon a
supply from a spring, its yield should be ascertained by one of the
well-known gauging methods. Springs are usually lowest in the months
of October and November, though there is some difference in this
respect between land springs and deep springs. The minimum yield of
the spring determines whether it forms a supply to be relied upon at
all times of the year.
If the spring is located higher than the grounds and buildings to be
supplied, a simple gravity supply line may be carried from it, with
pipes of good size, thus avoiding undue friction in the line, and
stoppages. If lower than the house, the water from the spring must be
raised by some pumping method.
All water found underground owes its origin to the rainfall. If
concealed water is returned to the surface by _natural processes_ it
is called spring water, but if recovered by _artificial means_ it is
called well water.
_Different Kinds of Wells_
There are numerous kinds of wells, distinguished from one another by
their mode of construction, by their depth from the surface, by the
fact of their piercing an impervious stratum or merely tapping the
first underground sheet of water, and by the height to which the water
in them rises or flows. Thus we have shallow and deep wells,
horizontal wells or infiltration galleries, open or dug wells, tube
wells, non-flowing and flowing wells, bored, drilled, and driven
wells, tile-lined and brick-lined wells, and combination
dug-and-tubular wells.
When it is desired to provide a water supply by means of wells some
knowledge of the geology of the region, of the character of the strata
and of their direction and dip, will be very useful. In the case of
deep wells, it is really essential. By making inquiries as to similar
well operations in the neighborhood, one may gain some useful
information, and thus, to some extent, avoid guesswork. When one must
drill or bore through rock for a very deep well, which necessarily is
expensive, much money, often uselessly spent, may be saved by
consulting the reports of the State geologist, or the publications of
the United States Geological Survey, or by engaging the services of an
expert hydrogeologist.
"_Water Finders_"
It used to be a common practice to send for so-called "water finders,"
who being usually shrewd observers would locate by the aid of a hazel
twig the exact spot where water could be found. In searching for water
one sometimes runs across these men even to-day. The superstitious
faith in the power of the forked twig or branch from the hazelnut bush
to indicate by its twisting or turning the presence of underground
water was at one time widespread, but only the very slightest
foundation of fact exists for the belief in such supernatural powers.
In Europe, attention has again, during the past years, been called to
this "method" of finding water, and it has even received the
indorsement of a very high German authority in hydraulic engineering,
a man well up in years, with a very wide practical experience, and the
author of the most up-to-date hand-book on "Water Supply," but men of
science have not failed to contradict his statements.
_Definition of "Ground-water Level"_
Water percolating through the soil passes downward by gravity until it
reaches an impervious stratum. The surface of this underground sheet
of water is technically called "water table" or ground-water level.
The water is not at rest, but has a slow and well-defined motion, the
rate of which depends upon the porosity of the soil and also upon the
inclination or gradient of the water table. A shallow well may be
either excavated or driven into this subsoil sheet of water. In
populous districts, in villages, towns, but also near habitations, the
soil from which water is obtained must, of necessity, be impregnated
with organic waste matter. If, in such a surface well, the level of
the water is lowered by pumping, the zone of pollution is extended
laterally in all directions. Ordinary shallow well water should always
be considered "suspicious water." There are two distinct ways in which
surface wells are contaminated: one is by leakage from cesspools,
sewers, privies, etc.; the other, just as important and no less
dangerous, by direct contamination from the surface. The latter
danger is particularly great in wells which are open at the surface,
and from which water is drawn in buckets or pails. A pump well is
always the safer of the two. Frogs, mice, and other small animals are
apt to fall into the water; dust and dirt settle into it; the wooden
curb and the rotten cover also contribute to the pollution; even the
draw-buckets add to it by reason of being often handled with unclean
hands.
Always avoid, in the country, drinking water from farmers' wells
located near cesspools or privies. Such shallow wells are particularly
dangerous after a long-protracted drought. It is impossible to define
by measurement the distance from a cesspool or manure pit at which a
well can be located with safety, for this depends entirely upon local
circumstances. Contamination of shallow wells may, in exceptional
cases, be avoided by a proper location of the well with reference to
the existing sources of impurity. A well should always be placed
_above_ the source of pollution, using the word "above" with reference
to the direction in which the ground water flows.
_Precautions Regarding Wells_
Other precautions to be observed with reference to surface wells are
the following:
Never dig a well near places where soil contamination has taken or is
taking place. Line the sides of the well with either brick, stone, or
tile pipe, cemented in a water-tight manner to a depth of at least
twenty feet from the surface, so that no water can enter except from
the bottom, or at the sides near the bottom.
Raise the surface at the top of the well above the grade; arrange it
so as to slope away on all sides from the well; cover it with a
flagstone, and cement the same to prevent foreign matters from
dropping into the well; make sure that no surface water can pass
directly into the well; make some provision to carry away waste water
and drippings from the well.
Shallow wells made by driving iron tubes with well points into the
subsoil water are preferable to dug wells. Use a draw-pump in
preference to draw buckets.
When a well is sunk through an impervious stratum to tap the larger
supply of water in the deeper strata, we obtain a "deep well." Water
so secured is usually of great purity, for the impurities have been
filtered and strained out by the passage of the water through the
soil. Moreover, the nature of the construction of deep wells is such
that they are more efficiently protected against contamination, the
sides being made impervious by an iron-pipe casing. In some rare
cases, even deep wells show pollution due to careless jointing of the
lining, or water follows the outside of the well casing until it
reaches the deeper water sheet. Deep wells usually yield more water
than shallow driven wells, and the supply increases perceptibly when
the water level in the well is lowered by pumping. While surface
wells draw upon the rainfall percolating in their immediate vicinity,
deep wells are supplied by the rainfall from more remote districts.
Deep wells are either non-flowing or flowing wells. When the
hydrostatic pressure under which the water stands is sufficient to
make it flow freely out on the surface or at the mouth of the well, we
have a flowing, or true artesian well.
_Character of Water From Deep Wells_
Water from deep wells is of a cool and even temperature. It is usually
very pure, but in some cases made hard by mineral salts in the water.
Sulphur is also at times present, and some wells on the southern
Atlantic coast yield water impregnated with sulphur gases, which,
however, readily pass off, leaving the water in good condition for all
uses. In many cases the water has a taste of iron. No general rule can
be quoted as to the exact amount of water which any given well will
yield, for this depends upon a number of factors. Increasing the
diameter of very deep wells does not seem to have any marked effect in
increasing the supply. Thus, a two-foot well gives only from fifteen
to thirty per cent more water than a three-inch-pipe well. This rule
does not seem to apply to shallow wells of large diameter, for here we
find that the yield is about in proportion to the diameter of the
well.
It is interesting to note the fact that wells located near the
seashore, within the influence of the tide, vary in the hourly flow.
According to Dr. Honda, of the University of Tokio, there is "a
remarkable concordance between the daily variations in the level of
the tides and the water level in wells." The water in wells one mile
from the seashore was found to stand highest at high tide. The daily
variation amounted to sixteen centimeters, or a little over six
inches. A similar variation was observed by the writer in some flowing
wells located on the north shore of Long Island. Dr. Honda found also
that the water level in wells varied with the state of the barometer,
the water level being lowered with a rise in the barometer.
Where a large supply is wanted a series of wells may be driven, and,
as the expense involved is considerable, it is always advisable to
begin by sinking a smaller test well to find out whether water may be
had.
Ground water may also be recovered from water-bearing strata by
arranging horizontal collecting galleries with loose-jointed sides
through which the water percolates. Such infiltration galleries have
been used in some instances for the supply of towns and of
manufacturing establishments, but they are not common for the supply
of country houses.
_Laws Regulating Appropriation of Water_
Persons contemplating the establishment of a system of water supply in
the country should bear in mind that the taking of water for supply
purposes is, in nearly all States, hemmed in by legal restrictions.
The law makes a distinction between subterranean waters, surface
waters flowing in a well-defined channel and within definite banks,
and surface waters merely spread over the ground or accumulated in
natural depressions, pools, or in swamps. There are separate and
distinct laws governing each kind of water. It is advisable, where a
water-supply problem presents itself, to look up these laws, or to
consult a lawyer well versed in the law of water courses.
If it is the intention to take water from a lake, the property owner
should make sure that he owns the right to take such water, and that
the deed of his property does not read "to high-water mark only." The
owner of a property not abutting on a lake has no legal right to
abstract some of the water from the lake by building an infiltration
gallery, or a vertical well of large diameter intended for the same
purpose. On the other hand, an owner may take subterranean water by
driving or digging a well on his own property, and it does not matter,
from the law's point of view, whether by so doing he intercepts partly
or wholly the flow of water in a neighboring well. But, if it can be
shown that the subterranean water flows in a well-defined channel, he
is not permitted to do this. The water from a stream cannot be
appropriated or diverted for supply or irrigation purposes by a single
property holder without the consent of the other riparian owners, and
without compensation to them.
CHAPTER II
=Appliances for Distributing Water=
We have so far discussed only the various sources of potable water. We
must now turn our attention to the mechanical means for making it
available for use, which comprise appliances for lifting, storing,
conveying, distributing, and purifying the water.
The location of the source of supply with reference to the buildings
and grounds decides generally the question whether a gravity supply is
feasible or whether water must be pumped. The former is desirable
because its operating expenses are almost nothing, but it is not
always cheapest in first cost. Rather than have a very long line of
conduit, it may be cheaper to pump water, particularly if wind or
water power, costing nothing, can be used.
_Machines for Pumping_
When it becomes necessary to pump water, there are numerous machines
from which to choose; only the more important ones will be considered.
We may use pumps operated by manual labor, those run by animal power,
pumping machinery using the power of the wind or that of falling or
running water; then there are hot-air, steam, and electric pumps,
besides several forms of internal-combustion engines, such as gas,
gasoline, and oil engines. Each has advantages in certain locations
and under certain conditions.
Of appliances utilizing the forces of Nature, perhaps the simplest
efficient machine is the hydraulic ram. While other machines for
lifting water are composed of two parts, namely, a motor and a pump,
the ram combines both in one apparatus. It is a self-acting pump of
the impulse type, in which force is suddenly applied and discontinued,
these periodical applications resulting in the lifting of water.
Single-acting rams pump the water which operates them; double-acting
rams utilize an impure supply to lift a pure supply from a different
source.
The advantages of the ram are: it works continuously, day and night,
summer and winter, with but very little attendance; no lubrication is
required, repairs are few, the first cost of installation is small.
Frost protection, however, is essential. The disadvantages are that a
ram can be used only where a large volume of water is available. The
correct setting up is important, also the proper proportioning in size
and length of drive and discharge pipes. The continual jarring tends
to strain the pipes, joints, and valves; hence, heavy piping and
fittings are necessary. A ram of the improved type raises water from
twenty-five to thirty feet for every foot of fall in the drive pipe,
and its efficiency is from seventy to eighty per cent.
Running water is a most convenient and cheap power, which is often
utilized in water wheels and turbines. These supply power to run a
pump; the water to be raised may come from any source, and the pump
may be placed at some distance from the water wheel. Where sufficient
fall is available--at least three feet--the overshot wheel is used. In
California and some other Western States an impulse water wheel is
much used, which is especially adapted to high heads.
_Windmills Used for Driving Pumps_
The power of the wind applied to a windmill is much used for driving
pumps. It is a long step forward from the ancient and picturesque
Dutch form of windmill, consisting of only four arms with cloth sails,
to the modern improved forms of wheels constructed in wood and in
iron, with a large number of impulse blades, and provided with devices
regulating the speed, turning the wheel out of the wind during a gale,
and stopping it automatically when the storage tank is filled. The
useful power developed by windmills when pumping water in a moderate
wind, say of sixteen miles an hour velocity, is not very high, ranging
from one twenty-fifth horse-power for an eight and one-half foot wheel
to one and one-half horse-power for a twenty-five foot wheel. The
claims of some makers of windmills as to the power developed should be
accepted with caution.
The chief advantage is that, like a ram, the windmill may work night
and day, with but slight attention to lubrication, so long as the wind
blows. But there are also drawbacks; it requires very large storage
tanks to provide for periods of calm; the wheel must be placed
sufficiently exposed to receive the full wind force, either on a tower
or on a high hill, and usually this is not the best place to find
water. Besides, a windmill tower, at least the modern one, is not an
ornamental feature in the landscape. It is expensive when built
sufficiently strong to withstand severe winter gales. During the hot
months of the year, when the farmer, the gardener, and the coachman
require most water, the wind is apt to fail entirely for days in
succession.
_The Use of Engines_
If water is not available, and wind is considered too unreliable,
pumping must be accomplished by using an engine which, no matter of
what form or type, derives its energy from the combustion of fuel, be
the same coal, wood, charcoal, petroleum or kerosene, gas, gasoline,
or naphtha. The use of such pumping engines implies a constant expense
for fuel, operation, maintenance, and repairs. In some modern forms of
engines this expense is small, notably so in the oil engine, and also
in the gasoline engine; hence these types have become favorites.
_Advantages of Pumping Engines_
An advantage common to all pumping engines is that they can be run at
any time, not like the windmill, which does not operate in a light
breeze, nor like the ram, which fails when the brook runs low.
Domestic pumping engines are built as simple as possible, so that the
gardener, a farm hand, or the domestic help may run them. Skill is not
required to operate them, and they are constructed so as to be safe,
provided ordinary intelligence is applied.
In using a fuel engine it is desirable, because of the attendance
required, to take a machine of such capacity and size that the water
supply required for two or three days may be pumped to the storage
tank in a few hours.
_Expansive Force of Heated Air Utilized_
A favorite and extensively used type of domestic pump is the hot-air
engine, in which the expansive force of heated air is used to do
useful work. Among the types are simple and safe machines which do not
easily get out of order. They are started by hand by giving the fly
wheel one or more revolutions. If properly taken care of they are
durable and do not require expensive repairs.
_Gas and Gasoline Engines_
In gas engines power is derived from the explosion of a mixture of gas
and air. Where a gas supply is available, such engines are very
convenient, for, once started, they will run for hours without
attention. They are economical in the consumption of gas, and give
trouble only where the quality of gas varies.
Owing to the unavailability of gas on the farm and in country houses,
two other forms of pumping engines have been devised which are
becoming exceedingly popular. One is the gasoline, the other is the
oil engine. Both resemble the gas engine, but differ from it in using
a liquid fuel which is volatilized by a sprayer. Gasoline engines are
now brought to a high state of perfection.
_Kerosene or Crude Oil as Fuel_
In recent years, internal-combustion engines which use heavy kerosene
or crude oil as fuel have been introduced. These have two palpable
advantages: first, they are safer than gasoline engines; second, they
cost less to run, for crude oil and even refined kerosene are much
cheaper than gasoline. Oil engines resemble the gas and gasoline
engines, but they have larger cylinders, because the mean effective
pressure evolved from the explosion is much less than that of the
gasoline engines.
Oil engines for pumping water are particularly suitable in regions
where coal and wood cannot be obtained except at exorbitant cost.
Usually, the engine is so built as to be adapted for other farm work.
It shares this advantage with the gasoline engine. Oil engines are
simple, reliable, almost automatic, compact, and reasonable in first
cost and in cost of repairs. There are many forms of such engines in
the market. To be successful from a commercial point of view, an oil
engine should be so designed and built that any unskilled attendant
can run, adjust, and clean it. The cost of operating them, at eight
cents per gallon for kerosene, is only one cent per hour per
horse-power; or one-half of this when ordinary crude oil is used. The
only attention required when running is periodical lubrication and
occasional replenishing of the oil reservoir. The noise of the
exhaust, common to all engines using an explosive force, can be
largely done away with by using a muffler or a silencer. The smell of
oil from the exhaust likewise forms an objection, but can be overcome
by the use of an exhaust washer.
_Steam and Electric Pumps_
The well-known forms of steam-pumping engines need not be considered
in detail, because high-pressure steam is not often available in
country houses. Where electric current is brought to the building, or
generated for lighting purposes, water may be pumped by an electric
pump. Electric motors are easy and convenient to run, very clean, but
so far not very economical. Electric pumps may be arranged so as to
start and stop entirely automatically. Water may be pumped, where
electricity forms the power, either by triplex plunger pumps or by
rotary, screw, or centrifugal pumps.
_Pumps Worked by Hand_
Space forbids giving a description of the many simpler devices used
for lifting water. In small farmhouses lift and force pumps worked by
hand are now introduced, and the old-fashioned, moss-covered
draw-bucket, which is neither convenient nor sanitary, is becoming a
relic of past times.
_Reservoirs and Storage Tanks_
The water pumped is stored either in small masonry or earth
reservoirs, or else in storage tanks of either wood, iron, or steel,
placed on a wood or steel tower. Wooden tanks are cheap but unsightly,
require frequent renewal of the paint, and give trouble by leaking,
freezing, and corrosion of hoops. In recent years elevated tanks are
supplanted by pressure tanks. Several such systems, differing but
little from one another, are becoming quite well known. In these water
is stored under suitable pressure in air-tight tanks, filled partly
with water and partly with air.
_A Simple Pressure System_
One system consists of a circular, wrought-steel, closed tank, made
air- and water-tight, a force pump for pumping water into the tank,
and pipe connections. The tank is placed either horizontally or
vertically in the basement or cellar, or else placed outdoors in the
ground at a depth below freezing. Water is pumped into the bottom of
the tank, whereby its air acquires sufficient pressure to force water
to the upper floors.
This simple system has some marked advantages over the outside or the
attic tank. In these, water gets warm in summer and freezes in winter.
Vermin and dust get into the tank, and the water stagnates. In the
pressure tank, water is kept aerated, cool, and clean.
Another pressure tank has an automatic valve, controlled by a float
and connected with suction of pump. It prevents the tank from becoming
water-logged by maintaining the correct amount of air inside.
_An Ideal System for a Country House_
Still another system using pressure tanks is more complete than either
of the others, comprising engine, pump, air compressor, a water tank,
and also an air tank. It is best described by a recent example
constructed from plans and under the direction of the writer. The
buildings supplied with water comprise the mansion, the stable, the
cottage, and a dairy, and the pumping station is placed near the
shore of the lake from which the supply is taken. See Figs. 1 and 2.
[Illustration: FIG. 1.
DIAGRAM OF COMPRESSED AIR TANK SYSTEM.]
[Illustration: FIG. 2.
PRESSURE-TANK PUMPING STATION.
Interior view of pumping station of compressed air-tank system (see
plan on opposite page) showing 3,000 gallon water tank, air tank of
150 pounds pressure and 10 horse-power gasoline engine.]
The pump house is about 20 feet by 27 feet, and contains a
water-storage tank 6 feet in diameter and 13-1/2 feet long, of a
capacity of 3,000 gallons; an air tank of same dimensions as the water
tank, holding air under 150 pounds pressure; a 10 horse-power gasoline
engine, direct-connected, by means of friction clutch, with an air
compressor and also with a triplex pump of 75 gallons capacity per
minute.
The water in the tank is kept under 75 pounds pressure, and at the
hydrant near the house, located about 100 feet above the pumping
station, there is an available pressure of 33 pounds. The last drop of
water flows from the water tank under the full pressure of 75 pounds
at the pumping station. The suction pipe into the lake is 4 inches and
is provided with well strainers to prevent clogging.
The cost of pumping water by this system is quite reasonable. The
gasoline engine requires per horse-power per hour about 1-1/4 gallons
of gasoline, and at sixteen cents per gallon this makes the cost for
1,000 gallons pumped about five cents. To this expense should,
however, be added the cost of lubricating oil, repairs, amount for
depreciation, and the small cost for labor in running the engine.
Water pipes forming a distribution system should always be chosen
generous in diameter, in order to avoid undue loss of pressure by
friction. Where fire hydrants are provided, the size of the water main
should not be below four inches. All branches should be controlled by
shut-offs, for which the full-way gate valves are used in preference
to globe valves. Pipe-line material is usually galvanized,
screw-jointed wrought iron for sizes up to four inches.
In conclusion, a word about water purification. Where the quality of
the water supply is not above suspicion it may be improved by
filtration. A filter should never be installed without the advice of a
qualified expert, for there are numerous worthless devices and few
really efficient ones. Where a filter is not available, the water used
for drinking should be boiled or sterilized if there is the slightest
doubt as to its wholesomeness.
CHAPTER III
=Purifying Water by Copper Sulphate=
From the standpoint of the health of the community, the most vital
problem is to get pure water. Almost equally important, when comfort
and peace of mind is considered, is the procuring of sweet water. The
wise owner of a country home looks to the water supply upon which his
family is dependent. The careful farmer is particular about the water
his stock, as well as his family, must drink. But careless persons
constitute the large majority. Most people in the city and in the
country pay no attention to their drinking water so long as it "tastes
all right."
_Clear Water Often Dangerous_
Some years ago the inhabitants of Ithaca, N. Y., furnished a pitiful
example of this foolhardy spirit. For a year previous to the breaking
out of the typhoid epidemic, the public was warned, through the local
and the metropolitan press, of the dangerous condition of Ithaca's
water supply. Professors of Cornell College joined in these warnings.
But the people gave no heed, probably because the water was _clear_
and its taste sweet and agreeable. As was the case in this instance,
bacteria are tolerated indefinitely, and it is only an alarming
increase in the death rate that makes people careful. Then they begin
to boil the water--when it is too late for some of them.
_Bad-Tasting Water not Always Poisonous_
But let the taste become bad and the odor repulsive, and a scare is
easily started. "There must be dead things in the water, or it
wouldn't taste so horrible," is the common verdict. Some newspaper
seizes upon the trouble and makes of it a sensation. The ubiquitous
reporter writes of one of "the animals" that it "looks like a wagon
wheel and tastes like a fish." With such a remarkable organism
contaminating one's drink no wonder there is fear of some dread
disease. The water is believed to be full of "germs"; whereas the
pollution is entirely due to the presence of algae--never poisonous to
mankind, in some cases acting as purifying agents, but at certain
seasons of the year imparting a taste and odor to the water that
cannot be tolerated.
Algae--what are they? They are aquatic plants. Algae are not to be
confounded with the water vegetation common to the eye and passing by
the term weeds. Such plants include eelgrass, pickerel weed, water
plantain, and "duckmeat"--all of which have roots and produce flowers.
This vegetation does not lend a bad odor or taste to the water. In
itself it is harmless, although it sometimes affords a refuge for
organisms of a virulent type.
But when the aquatic vegetation of the flowering variety is eliminated
from consideration, there still remains a group of water plants called
algae. They comprise one-fifth of the known flowerless plants. They are
the ancestors of the entire vegetable kingdom. Those whose habitat is
the sea number the largest plants known in nature. Certain forms found
in the Pacific are supposed to be 800 feet in length; others are
reported to be 1,500 feet long. The marine variety are familiar as the
brown kelps and the wracks, which are very common along our Northern
coast.
_Plants Which Pollute Drinking Water_
The fresh-water algae are usually grass green in color. This green
variety is often seen as a spongy coating to the surface of stagnant
pools, which goes by the name of "frog spawn" or "pond scum." One of
this description, _Spirogyra_, has done thousands of dollars' worth of
damage by smothering the life out of young water-cress plants in
artificial beds constructed for winter propagation. When the cress is
cut the plants are necessarily left in a weakened condition, and the
algae form a thick mat over the surface of the water, thus preventing
the growth of the cress plants and oftentimes killing them. The
absolute necessity of exterminating these algae led to the perfection
of the copper-purification process.
It is, however, a variety of algae not easily detected that
contaminates the water. So long as they are in a live, healthy
condition they benefit drinking water by purifying it. Indeed, some
scientists have attributed the so-called self-purification of a stream
entirely to the activities of these plants. Of such, one form,
_Chlamydomonas_, is bright grass green in appearance. But the largest
group--the plants which have the worst reputation as polluters of
drinking water--are popularly known as the "blue-green algae"
(_Schizophyceae_). The common name tells the color of these plants,
although there are exceptions in this respect, some of them showing
shades of yellow, brown, olive, chocolate, and purplish red. This
variety of algae flourishes in the summer months, since a relatively
high temperature and shallow stagnant water favor its germination. If
the pond begins to dry up, the death of the organisms takes place, and
the result is a most disagreeable, persistent odor which renders the
water unfit for drinking purposes. This result is chemically due to
the breaking down of highly organized compounds of sulphur and
phosphorus in the presence of the large amount of nitrogen contained
in these plants. Decomposition is not necessary for some of the blue
greens to give off a bad odor, however. A number of them, on account
of their oil-content, produce an odor when in a healthy condition that
is sometimes likened to raw green corn or to nasturtiums, but usually
it cannot be so pleasantly described.
The Department of Agriculture has been able to solve the problem of
exterminating algae from water supplies.[1] The department has done
more; for it has succeeded in perfecting a method by which a reservoir
contaminated with typhoid or other pathogenic bacteria can be
purified. The work was begun with an inquiry into the extent of the
trouble from algal pollution. Letters were addressed to some five
hundred engineers and superintendents of water companies scattered all
over the United States. The replies, which came from almost every
State in the Union, were burdened with one complaint--"Algae are our
worst pest"; and with one prayer--"Come over into Macedonia, and help
us."
_A Cheap and Available Remedy for Algae_
Convinced of the need of earnest work, extensive laboratory
experiments were inaugurated. The problem presented was this: the
remedy must not only be readily available, but it must be cheap, that
advantage may be taken of it by the poorest communities, as well as by
those owning large reservoirs. Above all, the remedy must be
absolutely harmless to man; the poison used to exterminate algae must
not in any way affect the water drinkers. A large number of
substances were used in the experiments before the final decision
rested with copper sulphate. This salt is very poisonous to algae. On
the other hand, copper in solution just strong enough to destroy algal
growth could not possibly injure man; in fact, the temporary presence
of such a small amount of copper in drinking water could not be
detected.
_A Practical Demonstration_
The results in the laboratory being successful, the next step was to
make a practical demonstration of the value of the method. This was
first done in the fall of 1901. At Ben, Va., water cress is grown in
large quantities during the winter, when it is a valuable market crop.
Dams are constructed across a stream in such a manner as to enable the
maintenance of a water level not too high for the growth of plants;
when a freeze is threatened the plants can be flooded. In the cress
beds selected for the experiments the water is obtained from a thermal
spring whose temperature throughout the year is about 70 deg. F. This
temperature is particularly favorable to the growth of "frog spawn."
After the cress was cut for market, the algae frequently developed so
rapidly as to smother the life out of the weakened plants. When this
occurred, the practice was to rake out both water cress and algae and
reset the entire bed. This was not only expensive; half the time it
failed to exterminate the pest. It was, therefore, most desirable to
devise a method of ridding the bed of algal growth without injuring
the cress.
_The Copper-sulphate Method Tested_
Here the copper-sulphate method was put to a practical test. At the
outset a strong solution was sprayed on the algae which coated the
surface of the pond. This only killed the algal growth with which the
particles of copper came in contact and left the main body of algae
unaffected. Then trial was made of dissolving the copper directly in
the water, and the result was most satisfactory. The solution used was
that of 1 part of copper to 50,000,000 parts of water.
Growers need have no trouble in the future. They need have no fear of
employing the method, as the copper solution required for killing the
algae could not possibly injure water cress, provided ordinary care is
used in the work. As to the frequency of treatment required, one or
two applications a year will generally be found sufficient, as this
letter, received from the manager of the Virginia company, goes to
show:
"The 'moss' has given me no trouble at all this winter; in fact, I
have for six months had to resort to the copper sulphate only once....
All the conditions were favorable last fall and early winter for a
riot of 'moss,' but it did not appear at all until just a few days
ago, and then yielded to treatment much more readily than it did when
I first began to use the copper." This letter was written over three
years after Dr. Moore made his experiment in these cress beds.
Satisfied with the results attained in exterminating algal growth in
water-cress beds, attention was next given to reservoirs. Some fifty
water supplies were treated during the summer of 1904, and in every
case success attended the copper cure. In one respect the results were
surprising. It was found that in practice the copper-sulphate method
worked better than in theoretic experimentation; results in large
reservoirs were more pronounced than in the laboratory. In fact, it
developed that the solution necessary to kill algae in the laboratory
must contain from five to twenty times as much copper as that
contained in a solution which will exterminate algal growth in its
natural habitat. This is not easily explained, if it can be explained
at all. The test reason advanced is that only the most resistant
organisms stand transplanting to an artificial environment. But, after
all, the important point is that the new method works better in
practice than was expected.
_A Prescription for the Copper Cure_
Thus the department is able to announce that the process is no longer
in the experimental stage, and also to say what conditions must be
known in determining the proper quantity of copper sulphate for
destroying algae, together with a prescription for the copper cure.
Here it is, for the benefit of careful persons who will use the method
with proper intelligence: "The importance of knowing the temperature
of the contaminated water is second only to the necessity of knowing
the organism present. With increase of temperature the toxicity of a
given dilution increases, and _vice versa_. Assuming that 59 deg. F. is
the average temperature of reservoirs during the seasons when
treatment is demanded, the quantity of copper should be increased or
decreased approximately 2.5 per cent for each degree below or above
59 deg. F.
"Similar scales should be arranged for the organic content and the
temporary hardness of the water. With the limited data at hand it is
impracticable to determine these figures, but an increase of 2 per
cent in the quantity of copper for each part per 100,000 of organic
matter and an increase of 0.5 to 5 per cent in the proportion of
copper for each part per 100,000 of temporary hardness will possibly
be found correct. The proper variation in the increase due to hardness
will depend upon the amount of dissolved carbon dioxide; if very
small, 5 per cent increase is desirable; if large, 0.5 per cent is
sufficient."
The information in this prescription is to be used in connection with
a table[2] published by the Department of Agriculture. This table
gives the number of parts of water to one part of copper sulphate
necessary to kill the various forms of algae which are listed. The
formulae vary from 1 part of copper to 100,000 parts of water,
necessary to destroy the most resistant and very rare forms (three of
these are listed), to 1 part of copper in 25,000,000 parts of water,
which is a sufficiently strong solution to exterminate _Spirogyra_,
the cress-bed pest. By far the majority of forms do not require a
solution stronger than that of 1 part of copper to 1,000,000 parts of
water.
_What the Agricultural Department is Doing_
It is true that the department is not now holding out, directly, a
helping hand to the owner of a country place, or to the farmer, in
this campaign of purifying drinking water. In the first place, the
greatest good of the greatest number demands that large reservoirs,
which supply a great number of people with drinking water, ought to be
considered first. Such supplies, moreover, are most frequently
contaminated. Where fifty reservoirs were treated last summer, ten
times that number will be "cured" this summer. It will be readily
seen, therefore, that in conducting such a large number of
experiments--considering preliminary reports, prescribing for
treatment, and keeping proper account of results--the department, with
a limited force and limited facilities, has its hands more than full.
More important still, there is an absolute need of the services of
some expert on the ground. While an algologist is a functionary not
generally employed by water companies--in fact, a man trained in the
physiology of algae is difficult to find--nevertheless, it is highly
important, as the department views it, to have the cooeperation of an
expert versed to some extent in the biological examination of drinking
water. In other words, the copper cure is not a "patent medicine,"
with printed directions which any person could follow. Intelligence
and care are absolutely essential in the use of this treatment.
Furthermore, each case must be treated as a distinct and separate
case, as a physician would treat a patient.
_Actual Purification Simple_
Suppose, however, an owner of a country place, which is dependent upon
a fresh-water pond for its water supply, finds that his drinking water
is contaminated, that the taste and odor are such as to render the
water unfit for use. There is no reason why he should not treat the
supply, provided he is properly careful. When the nature of the
polluting organism is definitely determined and the average
temperature of the water observed, then the necessary formula can be
decided upon. First, of course, the pond must be plotted, the depth
found, and the capacity computed. The department will willingly
furnish data for this purpose, together with blanks upon which to
submit details as to contaminating organisms and water temperature,
to any applicant. Once the proper solution is determined upon, the
actual work of purification is most simple. In the following
directions the department outlines the most practicable method of
introducing the copper sulphate into a water supply:
_Directions for the Copper Cure_
"Place the required number of pounds of copper sulphate in a coarse
bag--gunny sack or some equally loose mesh--and, attaching this to the
stern of a row-boat near the surface of the water, row slowly back and
forth over the reservoir, on each trip keeping the boat within ten to
twenty feet of the previous path. In this manner about a hundred
pounds of copper sulphate can be distributed in one hour. By
increasing the number of boats, and, in the case of deep reservoirs,
hanging two or three bags to each boat, the treatment of even a large
reservoir may be accomplished in from four to six hours. It is
necessary, of course, to reduce as much as possible the time required
for applying the copper, so that for immense supplies, with a capacity
of several billion gallons, it would probably be desirable to use a
launch, carrying long projecting spars to which could be attached bags
containing several hundred pounds of copper sulphate.
"The substitution of wire netting for the gunny-sack bag allows a more
rapid solution of the sulphate, and the time required for the
introduction of the salt may thus be considerably reduced. It is best
to select as warm a day for treatment as circumstances will permit."
_Cost of the Treatment_
Not difficult, one would say. No--when the proper solution is
determined; to reach that determination is the difficulty. That the
method can be tried "at home" is proved by the results obtained by the
owner of a country home in the vicinity of New York. Tired of
consulting engineers, who looked at his water supply, informed him
that they could do nothing, and then charged him a big fee (to one he
paid $250), this owner resorted to the copper-sulphate treatment. The
cure cost the man just $2--but let his letter to the department tell
the story:
"My place in the country is located at Water Mill, in the township of
Southampton, in Long Island. I purchased it in April, 1902, and was
largely influenced in selecting this piece of land by the beauty of a
pond which bounds it on the east. This little body of water covers
about two acres, is fed by numerous springs, and discharges into Mecox
Bay, the southern boundary of the land. When I bought the place the
pond was filled with clear water. About the middle of the following
June algae began to show, and in August the surface was almost entirely
covered by the growth. The odor was offensive, and myriads of small
insects hovered over the masses of algae much of the time. I consulted
two engineers interested in the storage of water, and they told me
that nothing could be done. The condition was so objectionable that I
planned to plant a thick hedge of willows along the bank to shut off
the view of the pond from the house.... I examined the pond on June
15th and found large masses of algae covering an area several hundred
feet in length and from twenty to forty feet in width. No
microscopical examination was made of the growth, but I was informed
that it seemed to be largely composed of filaments of _Spirogyra_ and
other _Confervae_. On June 18th the treatment was begun.... In one week
the growth had sunk and the pond was clear water. I examined the pond
September 15th and found it still clear.
"The use of the sulphate of copper converted an offensive
insect-breeding pond into a body of beautifully clear water. The pond
was full of fish, but the copper did not seem to harm them."
_Effect of Copper Sulphate on Fish_
Native trout were not injured when the large reservoir at Cambridge,
N. Y., was purified by the copper treatment. A slightly different
result, in this respect, was reported from Elmira, N. Y., however.
Part of the report is as follows:
"The effect of the copper-sulphate treatment on the different animal
life was as follows: numerous 'pollywogs' killed, but no frogs;
numerous small (less than two inches long) black bass and two large
ones (eight inches long) killed; about ten large 'bullheads' were
killed, but no small ones; numerous small (less than two inches long)
'sunfish' were killed, but no large ones.
"The wind brought the dead fish to the corners of the reservoir, and
it was very little trouble to remove them. No dead fish were seen
twenty-four hours after completion of the treatment."
The injury done by copper sulphate to fish is a more serious matter
than was at first supposed. Brook trout are, apparently, the least
resistant to the salt. A Massachusetts trout pond stocked with
eight-inch trout lost forty per cent as a result of the introduction
of a strong solution of copper sulphate. The Bureau of Fisheries is
working in conjunction with the Division of Plant Physiology in this
matter, and it is hoped to secure reliable information. In the
meantime, owners of ponds stocked with game fish would do well to take
great care before resorting to the copper cure for algae--that is, if
they hesitate to lose a part of the fish.
_Water May be Drunk During Treatment_
When a pond or reservoir is treated with the proper amount of copper
sulphate to remove algae--except in the case of the few very resistant
forms requiring a stronger solution than 1 part of copper to
1,000,000 parts of water--there is no need of discontinuing the use
of the water supply during treatment; the water may be drunk with
impunity. But when water known to be polluted with pathogenic bacteria
is sterilized by means of copper sulphate in strong solution, it is
just as well to discontinue the use of the water for drinking purposes
for not more than twenty-four hours. Even then, this is an overcareful
precaution rather than a necessity.
Experiments conducted with great care and thoroughness demonstrate
that at room temperature, which is near the temperature of a reservoir
in summer, a solution of 1 part of copper to 100,000 parts of water
will destroy typhoid bacteria in from three to five hours. Similar
experiments have proved that a copper solution of like strength is
fatal to cholera germs in three hours, provided the temperature is
above 20 deg. F. As was the case with algae, bacteria were found to be much
more sensitive to copper when polluting water than when grown in
artificial media.
_The Use of Copper Tanks_
The toxic effect of metallic copper upon typhoid bacteria in water
gives some hints as to prevention of the disease by the use of copper
tanks. This should not altogether take the place of the boiling of the
water; it is useful in keeping it free from contamination, although
water allowed to stand in copper receptacles for a period of from
twenty-four to forty-eight hours at room temperature would be
effectively sterilized, no matter what its contamination and no matter
how much matter it held in suspension. But in order to insure such
results the copper must be kept thoroughly clean. This polishing is
not, as was popularly supposed, to protect the consumer from "copper
poisoning," but to prevent the metal from becoming so coated with
foreign substances that there is no contact of the copper with the
water, hence no antiseptic quality.
Dr. Henry Kreamer, of Philadelphia, proved that within four hours
typhoid germs were completely destroyed by the introduction into the
polluted water of copper foil.
"Granting the efficiency of the boiling of water for domestic
purposes, I believe that the copper-treated water is more natural and
more healthful.... The intestinal bacteria, like colon and typhoid,
are completely destroyed by placing clean copper foil in the water
containing them.
"Pending the introduction of the copper treatment of water on a large
scale, the householder may avail himself of a method for the
purification of drinking water by the use of strips of copper foil
about three and one-half inches square to each quart of water, this
being allowed to stand overnight, or from six to eight hours at the
ordinary temperature, and then the water drawn off or the copper foil
removed."
Although a splendid antiseptic, copper in weak solution is not
harmful, no more so than the old copper utensils used by our
forefathers were harmful. Undoubtedly they were of benefit, and the
use of them prevented the growth of typhoid and other bacteria. People
of to-day might well go back to copper receptacles for drinking
water.
FOOTNOTES:
[1] For published reports of the work, see Bulletins 64 and 76, Bureau
of Plant Industry, U. S. Department of Agriculture; reports prepared
by Dr. George T. Moore and his assistant, Mr. Karl F. Kellerman.
[2] See Bulletin No. 76, supra.
CHAPTER IV
=Ridding Stagnant Water of Mosquitoes=
Because of the serious and often fatal injury it inflicts on man, the
most dangerous animal known is the mosquito. Compared with the evil
done by the insect pest, the cobra's death toll is small. This
venomous serpent is found only in hot countries, particularly in
India, while mosquitoes know no favorite land or clime--unless it be
Jersey. Arctic explorers complain of them. In Alaska, it is recorded
by a scientist that "mosquitoes existed in countless millions, driving
us to the verge of suicide or insanity." A traveler on the north shore
of Lake Superior, when the snow was several feet deep, and the ice on
the lake five feet in thickness, relates that "mosquitoes appeared in
swarms, literally blackening the banks of snow in sheltered places."
_Mosquitoes Responsible for Yellow Fever_
In the temperate zone this evil-breeding insect was, until recent
years, considered more in the light of an exasperating pest. It is now
known, however, that malaria is due entirely to the bites of
mosquitoes. But it is in the tropical countries that their deadliest
work is done. There, it has been proved beyond question, the
mosquitoes are responsible for the carriage of yellow fever. If, in a
yellow-fever ridden region, one were to live entirely in an inclosure,
carefully protected with proper screens--as certain entomologists
did--there practically would be no danger from the dread disease, even
if all other precautions were neglected.
_Effect of a Mosquito Bite_
The crime committed by the mosquito against its innocent victim, man,
is more in the nature of manslaughter than of murder, according to the
authorities. There is no _premeditated malice_. "A mosquito bites
primarily to obtain food," says a leading entomologist; "there is
neither malice nor venom in the intent, whatever there may be in the
act." There isn't great comfort in the intelligence conveyed by the
scientist, nor in his further observation:
"Theoretically, there would seem to be no reason why there should be
any pain from the introduction of the minute lancets of the insects,
and the small amount of bloodletting is usually a benefit rather than
otherwise. Unfortunately, however, in its normal condition the human
blood is too much inclined to clot to be taken unchanged into the
mosquito stomach; hence, when the insect bites, a minute droplet of
poison is introduced, whose function it is to thin out the fluid and
make it more suitable for mosquito digestion. It is this poison that
sets up the inflammation and produces the irritation or swelling....
The pain is caused entirely by the action of the poison in breaking up
the blood, and, as the first act of a biting mosquito is to introduce
the poison into the wound, the pain and inflammation will be the same,
whether the insect gets its meal or not. In fact, it has been said
that if a mosquito be allowed to suck its fill and then fly, the bite
will not itch, and there is just a basis of justification for this."
To make a scientific inquiry into the habits of the mosquito, and to
do it patiently, one should be far from the maddening swarms, or at
least effectively screened in. Then it would be possible to believe
the statement of the Government's entomologist that not "one mosquito
in a million" ever gets the opportunity to taste the blood of a
warm-blooded animal. As proof of this there are, in this country,
great tracts of marshy land never frequented by warm-blooded animals,
and in which mosquitoes are breeding in countless numbers. The point
is emphasized by the prevalence of mosquitoes in the arctic circle and
other uninhabited regions.
If this gory insect does not live by blood alone, how is it nourished?
Female mosquitoes are by nature vegetarians; they are plant feeders.
Why they should draw blood at all is a question which remains
unsolved by entomologists--as well as by the suffering victims. The
females have been observed sucking the nectar from flowers; obtaining
nutriment from boiled potatoes, even from watermelon rinds, from which
they extract the juice. As regards the blood habit, the male mosquito
is a "teetotaler." Just how this male insect lives, scientists have
not determined. He may not take nourishment at all. At any rate, the
mouth parts of the male are so different from those of the female that
it is probable his food is obtained differently. The male is often
seen sipping at drops of water, and a taste for molasses is ascribed
to the male mosquito by one authority.
_Presence of Mosquitoes Depends Upon Winds_
A common remark heard along the Jersey shore, also on Long Island, is
this: "When we have a sea breeze we are not troubled with mosquitoes,
but when there comes a land breeze they are a pest." While this
observation is true, the reasons therefore entertained by the
unscientific mind are erroneous. The matter of the absence or
abundance of mosquitoes in varying winds is closely related to the
inquiry which entomologists have made: how far will mosquitoes fly?
Says one investigator:
"The migration of mosquitoes has been the source of much
misapprehension on the part of the public. The idea prevalent at our
seaside resorts that a land breeze brings swarms of mosquitoes from
far inland is based on the supposition that these insects are capable
of long-sustained flight, and a certain amount of battling against the
wind. This is an error. Mosquitoes are frail of wing; a light puff of
breath will illustrate this by hurling the helpless creature away, and
it will not venture on the wing again for some time after finding a
safe harbor. The prevalence of mosquitoes during a land breeze is
easily explained. It is usually only during the lulls in the wind that
Culex can fly. Generally on our coast a sea breeze means a stiff
breeze, and during these mosquitoes will be found hovering on the
leeward side of houses, sand dunes, and thick foliage.... While the
strong breezes last, they will stick closely to these friendly
shelters, though a cluster of houses may be but a few rods off, filled
with unsuspecting mortals who imagine their tormentors are far inland
over the salt meadows. But if the wind dies down, as it usually does
when veering, out come swarms upon swarms of females intent upon
satisfying their depraved taste for blood. This explains why they
appear on the field of action almost immediately after the cessation
of the strong breeze; on the supposition that they were blown inland,
this sudden reappearance would be unaccountable."
A sultry, rainy period of midsummer is commonly referred to as "good
mosquito weather." The accepted idea is that mosquitoes are much more
abundant at such times. This is true, and the explanation is simple.
Mosquito larvae, or wrigglers, as they are termed, require water for
their development. A heavy shower leaves standing water, which, when
the air is full of moisture, evaporates slowly. Then, too, the heat
favors the growth of the microoerganisms on which the larvae feed;
wrigglers found in the water forty-eight hours after their formation
will have plenty of food, and adult mosquitoes will appear six to
eight days after the eggs are laid. Clear weather, with quick
evaporation, interferes with the development of the wrigglers, so that
a season with plenty of rain, but with sunshiny, drying weather
intervening, is not "good mosquito weather."
_Destroy the Larvae_
Inasmuch as a generation of mosquitoes appear to torment man within
ten days, at the longest, after the eggs are laid; as a batch laid by
a female mosquito contains from two hundred to four hundred eggs; as
from each egg may issue a larva or wriggler which in six days will be
an adult mosquito on the wing--it is to the destruction of the larvae
that attention should be directed. The larva is a slender organism,
white or gray in color, comprising eight segments. The last of these
parts is in the form of a tube, through which the wriggler breathes.
Although its habitat is the water, it must come to the surface to
breathe, therefore its natural position is head down and tail, or
respiratory tube, up. Now, if oil is spread on the surface of a pool
inhabited by mosquito larvae, the wrigglers are denied access to the
air which they must have. Therefore, they drown, just as any other
air-breathing animal would drown under similar circumstances.
_Best Preventive Measures_
As to the best methods to employ in ridding a country place, or any
other region, of mosquitoes, the directions furnished by Dr. L. O.
Howard, the Government entomologist, who has been a careful student of
the problem since 1867, are of great value:
"Altogether,[3] the most satisfactory ways of fighting mosquitoes are
those which result in the destruction of the larvae or the abolition of
their breeding places. In not every locality are these measures
feasible, but in many places there is absolutely no necessity for the
mosquito annoyance. The three main preventive measures are the
draining of breeding places, the introduction of small fish into
fishless breeding places, and the treatment of such pools with
kerosene. These are three alternatives, any one of which will be
efficacious and any one of which may be used where there are reasons
against the trial of the others."
_Quantity of Kerosene to be Used_
"The quantity of kerosene to be practically used, as shown by the
writer's experiments, is approximately one ounce to fifteen square
feet of water surface, and ordinarily the application need not be
renewed for one month.... The writer is now advising the use of the
grade known as lubricating oil, as the result of the extensive
experiments made on Staten Island. It is much more persistent than the
ordinary illuminating oils.... On ponds of any size the quickest and
most perfect method of forming a film of kerosene will be to spray the
oil over the surface of the water.... It is not, however, the great
sea marshes along the coast, where mosquitoes breed in countless
numbers, which we can expect to treat by this method, but the inland
places, where the mosquito supply is derived from comparatively small
swamps and circumscribed pools. In most localities people endure the
torment or direct their remedies against the adult insect only,
without the slightest attempt to investigate the source of the supply,
when the very first step should be the undertaking of such an
investigation.
"The remedy which depends upon draining breeding places needs no
extended discussion. Naturally the draining off of the water of pools
will prevent mosquitoes from breeding there, and the possibility of
such draining and the means by which it may be done will vary with
each individual case. The writer is informed that an elaborate bit of
work which has been done at Virginia Beach bears on this method.
Behind the hotels at this place, the hotels themselves fronting upon
the beach, was a large fresh-water lake, which, with its adjoining
swamps, was a source of mosquito supply, and it was further feared
that it made the neighborhood malarious. Two canals were cut from the
lake to the ocean, and by means of machinery the water of the lake was
changed from a body of fresh to a body of salt water. Water that is
somewhat brackish will support mosquitoes, but water that is purely
salt will destroy them."
_Employing Fish to Destroy Larvae_
"The introduction of fish into fishless breeding places is another
matter. It may be undesirable to treat certain breeding places with
kerosene, as, for instance, water which is intended for drinking,
although this has been done without harm in tanks where, as is
customary, the drinking supply is drawn from the bottom of the tank.
The value of most small fishes for the purpose of destroying mosquito
larvae was well indicated by an experience described to us by Mr. C. H.
Russell, of Bridgeport, Conn. In this case a very high tide broke away
a dike and flooded the salt meadows of Stratford, a small town a few
miles from Bridgeport. The receding tide left two small lakes, nearly
side by side and of the same size. In one lake the tide left a dozen
or more small fishes, while the other was fishless. An examination by
Mr. Russell in the summer of 1891 showed that while the fishless lake
contained tens of thousands of mosquito larvae, that containing the
fish had no larvae. The use of carp for this purpose has been
demonstrated, but most small fish will answer as well. The writer
knows of none that will be better than either of the common little
sticklebacks (_Gasterosteus aculeatus_ or _Pygosteus pungitius_)."
Is mosquito fighting a success? This question is an all-important one,
not only to the summer resident, but also to cities and towns
contiguous to salt-water marshes, or to swampy lands, well suited for
mosquito breeding. The answer is this: Mosquito control is possible;
actual extermination impossible with an insect that develops so
rapidly. The "Jersey mosquito," the unscientific name popularly given
to an insect of huge size and ravenous appetite, has become famous. As
a matter of fact, the species of mosquitoes found in New Jersey are no
more rare or varied than those found on Staten Island or on Long
Island. But until very recently the region lying between Jersey City
and Newark has been particularly favorable to the development of
mosquito larvae. It has been announced in the press that mosquitoes
have been driven out of the Newark meadows. This is an exaggeration,
of course, but the work accomplished there is remarkable, and other
infected regions may take heart from the marked success which has
attended the efforts of Dr. John B. Smith, Entomologist of the New
Jersey State Agricultural Experiment Station.
_Remarkable Work Accomplished_
The salt marsh lying within the limits of the city of Newark covers an
area of about 3,500 acres. It extends from a point on the Passaic
River to the mouth of Bound Creek, where it empties into Newark Bay.
Its length is about eight miles and it has an extreme width of three
miles. The Newark marsh problem was a very complex one. The meadows
are cut into many sections by the several traversing railroads and by
creeks; this materially influences the drainage. The Peddie Street
sewer crosses the marsh in a straight line of about three miles from
the city to the bay. This sewer is twenty feet wide, and its banks are
from three to four feet above the marsh land.
An experiment with machine ditching was made in 1903. The worst parts
of the marsh were selected, and about 40,000 feet of ditches were cut.
These ditches were six inches wide, two feet deep, and the drainage
was perfect from the outset. The section of meadow thus drained became
so dry in consequence that the grass growing there can now be cut by a
machine in summer, whereas formerly the hay could be mown only in
winter. The work was so successful that the Newark Common Council
appropriated $5,000 to complete the mosquito drainage of the marsh.
Of the results obtained up to this spring, Dr. Smith says:
"This Newark marsh problem was an unusual one, and one that would not
be likely to recur in the same way at any other point along the coast.
Nevertheless, of the entire 3,500 acres of marsh, not 100 acres remain
on which there is any breeding whatever, and that is dangerous only in
a few places and under certain abnormal conditions. Including old
ditches cleaned out, about 360,000 running feet of ditches have been
dug on the Newark marshes, partly by machine and partly by hand, and
if the work is not entirely successful, that is due to the defects
which were not included in the drainage scheme. It is a safe
prediction, I think, that Newark will have no early brood of
mosquitoes in 1905, comparable with the invasions of 1903 and 1904."
This prophecy has proved true.
_The Campaign on Long Island_
The wealthy summer residents along the north shore of Long Island,
keenly alive to the necessity of driving mosquitoes from the region
where they spend so much of their time, have attacked the problem in a
scientific, as well as an energetic way. The North Shore Improvement
Association intrusted the work to Henry Clay Weeks, a sanitary
engineer, with whom was associated, as entomologist, Prof. Charles B.
Davenport, Professor of Entomology at the University of Chicago and
head of the Cold Spring Biological Laboratory; also F. E. Lutz, an
instructor in biology at the University of Chicago. Prof. N. S.
Shaler, of Harvard University, the most eminent authority in the
country on marine marshes, was retained to make a special examination
of the salt marshes with a view to recommending the best means of
eliminating what were the most prolific breeding grounds of
mosquitoes. A detailed examination of the entire territory was made.
Practically every breeding place of mosquitoes, including the smaller
pools and streams, and even the various artificial receptacles of
water, were located and reported on. Mr. Weeks, with his assistant,
then examined each body of water in which mosquito larvae had been
found, with a view to devising the best means of preventing the
further breeding of mosquitoes in these plague spots. Finally, a
report was prepared, together with a map on which was located every
natural breeding place.
_Investigations in Connecticut_
Important investigations have been made in Connecticut by the
Agricultural Experiment Station, under the direction of W. E. Britton
and Henry L. Viereck, and the results have been most encouraging. Dr.
Howard, in his directions for fighting mosquitoes, acknowledges his
indebtedness to the very successful experiments carried on at Staten
Island. Maryland is aroused to the point of action. Dr. Howard A.
Kelley, of Johns Hopkins University, is to cooeperate with Thomas B.
Symons, the State entomologist, in carrying the war to the shores of
Chesapeake Bay. "Home talent," moreover, can accomplish much. To fight
intelligently, let it not be forgotten that the battle should be
directed against the larvae. These wrigglers are bred for aquatic life;
therefore, it is to all standing water that attention should be
directed. Mosquito larvae will not breed in large ponds, or in open,
permanent pools, except at the edges, because the water is ruffled by
the wind. Any pool can be rendered free from wrigglers by cleaning up
the edges and stocking with fish. Every fountain or artificial water
basin ought to be so stocked, if it is only with goldfish. The house
owner should not overlook any pond, however small, or a puddle of
water, a ditch, or any depression which retains water. A half-filled
pail, a watering trough, even a tin receptacle will likely be
populated with mosquito larvae. Water barrels are favorite haunts for
wrigglers.
_A Simple Household Remedy_
There are those, however, who will obstinately conduct their campaign
against the adult mosquito. If energetic, such persons will search the
house with a kerosene cup attached to a stick; when this is held
under resting mosquitoes the insects fall into the cup and are
destroyed. Those possessed of less energy daub their faces and hands
with camphor, or with the oil of pennyroyal, and bid defiance to the
pests. With others it is, Slap! slap!--with irritation mental as well
as physical; for the latter, entomologists recommend household
ammonia.
FOOTNOTES:
[3] See Bulletin No. 25, U. S. Department of Agriculture, Division of
Entomology.
Part II
PURE FOOD FOR THE
HOUSEKEEPER
BY
S. JOSEPHINE BAKER
CHAPTER I
=How to Detect Food Adulteration=
Adulteration when applied to foodstuffs is a broad, general term, and
covers all classes of misrepresentation, substitution, deterioration,
or addition of foreign substances; adulteration may be either
intentional or accidental, but the housekeeper should be prepared to
recognize it and so protect herself and her household.
Food is considered adulterated when it can be classified under any of
the following headings:
=DEFINITIONS OF ADULTERATION.=--(1) If any substance has been mixed or
packed with it so as to reduce or lower or injuriously affect its
quality or strength.
(2) If any inferior substance has been substituted for it, wholly or
in part.
(3) If any valuable constituent has been wholly or in part abstracted
from it.
(4) If it consists wholly or in part of diseased or decomposed or
putrid or rotten animal or vegetable substance, or any portion of an
animal unfit for food, whether manufactured or not, or if it is the
product of a diseased animal or one who has died otherwise than by
slaughter.
(5) If it be colored or coated or polished or powdered, whereby damage
is concealed or it is made to appear better than it really is.
(6) If it contains any added poisonous ingredient or any ingredient
which may render such article injurious to health; or if it contains
any antiseptic or preservative not evident or not known to the
purchaser or consumer.
=FOOD LAWS.=--There is now in effect in the United States a rigid law
against the offering for sale of any article intended for human
consumption which is adulterated in any way, without the fact and
nature of such adulteration being plainly stated on a label attached
to the package containing the article. This law, however, applies only
to articles of this nature which originate, or are produced, in one
State and offered for sale in another. The purchaser is, therefore, in
a great degree protected, but many foodstuffs or manufactured articles
may have their origin within the State wherein they are sold, and in
this case the only safeguards are those afforded by the laws of the
State, city, or town immediately concerned. If these restraining laws
do not exist or if they are not enforced the housekeeper must rely
upon her own efforts to protect her family from adulterated food.
=PERMISSIBLE ADULTERANTS.=--In this class are included articles having
a food value such as salt, sugar, vinegar, spices, or smoke used as
preservatives of meats; or starch when added to the salts composing
baking powder, where a certain amount is permissible for the purpose
of absorbing moisture.
=GENERAL DIRECTIONS.=--The ability to select fresh, wholesome meats,
poultry, fish, fruits, and vegetables, to determine readily the purity
of dairy products, and to detect adulteration or misrepresentation in
all classes of foodstuffs must, in most instances, be acquired. Common
sense and good reasoning powers are needed here as in every problem of
life. While some adulterants can be detected only by trained chemists
and by means of tests too difficult and involved for general use, the
average housekeeper may amply protect herself from gross imposition by
simply cultivating her powers of observation and by making use of a
few simple tests well within her grasp and easily applied.
=First--Sight, Taste, and Smell.=--All are of prime importance in
determining the freshness and wholesomeness of foods, especially
meats, poultry, fish, vegetables, and fruits. Avoid all highly colored
bottled or canned fruits or vegetables; pure preserved fruits, jams,
jellies, or relishes may have a good bright color, but never have the
brilliant reds and greens so often shown in the artificially colored
products.[4] The same is true of canned peas, beans, or Brussels
sprouts; here the natural product is a dull, rather dingy green, and
all bright green samples must be suspected. Foreign articles of this
class are the worst offenders.
All food products should have a clean wholesome odor, characteristic
of their particular class. The odor of decomposition can be readily
detected; stale and musty odors are soon recognized.
It should be rarely necessary to use the sense of taste, but any food
with a taste foreign to the known taste of a similar product of known
purity should be discarded or at least suspected.
=Second--Price.=--Remember that the best and purest food, however high
priced, is cheapest in the end. Its value in purity, cleanliness, food
value, and strength gives a greater proportionate return than foods
priced lower than one might legitimately expect from their supposed
character. To cite a few instances: pure Java and Mocha coffee cannot
be retailed at twenty cents per pound; therefore, when the housekeeper
pays that price she must expect to get chicory mixed with the coffee;
if it contains no other adulterant, she may consider herself
fortunate. Cheap vanilla is not made from the vanilla bean. These
beans sell at wholesale for from ten to fifteen dollars a pound, and
the cheap extracts are made from the Tonka bean or from a chemical
product known as vanillin. These substances are not harmful, but they
are not vanilla. Pure virgin olive oil is made from the flesh of
olives after the stones and skin have been removed; cheaper grades are
made from the stones themselves and have little food value, while the
virgin oil is one of the most nutritious and wholesome of foods.
Such instances might be cited almost without end. Good, pure food
demands a good price, and economy defeats its own purpose when it is
practiced at the expense of one of the most vital necessities of
health and life.
=Third--Reliable Dealers.=--Select your tradesmen with the same care
you bestow in the choice of a physician. A grocer or butcher who has
once sold stale, adulterated, or impure wares has forfeited his right
to be trusted. A man who is honestly trying to build up a good trade
must have the confidence of his customers and it is to his interest to
sell only worthy goods; this confidence he can gain only by proving
his trustworthiness. When you are convinced of your dealer's honesty
give him your trade and do not be lured away by flashy advertisements
and the promise of "something for nothing."
=PREPARATION FOR CHEMICAL TESTS.=--Although the housekeeper will
rarely need the use of any chemical tests for the purpose of
determining the purity of food, the following directions must be kept
in mind if such an expedient is deemed necessary. It will be wise,
however, in the majority of cases when the presence of chemical
preservatives and adulterants is suspected, to send the article to a
chemist for analysis.
1. All refuse matter, such as shells, bones, bran, and skin, must be
removed from the edible portion of the food to be tested.
2. If the sample is solid or semi-solid, divide it as finely as
possible. All vegetables and meats may be minced in the common
household chopping machine. Tea, coffee, whole spices, and the like
may be ground or crushed in a mortar or in a spice mill.
3. Milk must be thoroughly stirred or shaken so that the cream is well
mixed with the body of the milk.
=FLESH FOODS--Meat.=--Fresh, wholesome meat is neither pink nor
purple; these colors indicate either that the animal was not
slaughtered or that it was diseased. Good meat is firm and elastic and
when dented with the finger does not retain the impression; it has the
same consistency and color throughout; the flesh is marbled, due to
the presence of fat distributed among the muscular fibers; it will
hardly moisten the finger when touched; it has no disagreeable odor
and has a slightly acid reaction so that red litmus paper applied to
it should not turn blue.
Wet, sodden, or flabby meat with jellylike fat, a strong putrid odor,
and alkaline reaction should be avoided. These signs indicate
advanced decomposition, and such meat is unfit for food.
=Beef.=--This meat should have a fine grain, be firm in texture, with
rosy-red flesh and yellowish-white fat.
=Lamb and Mutton= should have a clear, hard, white fat with the lean
part juicy, firm, and of rather light-red color. The flesh should be
firm and close of grain.
=Veal.=--The meat should not be eaten unless the animal was at least
six weeks old before slaughtering. The sale of this immature veal, or
"bob veal" as it is sometimes called, is prohibited by law in many
States. It is unwholesome and may be recognized by its soft, rather
mushy consistency and bluish tinge. Good veal has a firm white fat
with the lean of a pale-red color.
=Pork.=--This meat when fresh has a fat that is solid and pure white;
if yellow and soft it should be rejected; the lean is pink and the
skin like white translucent parchment.
=Poultry.=--Good poultry is firm to the touch, pink or yellowish in
color, is fairly plump, and has a strong skin showing an unbroken
surface. It has a fresh odor.
Stale poultry is flabby and shows a bluish color; it becomes green
over the crop and abdomen, and the skin is already broken or easily
pulled apart in handling. The odor of such a bird is disagreeable and
may even be putrid.
=Fish.=--With the exception of the salted or preserved varieties fish
should always be perfectly fresh when eaten. Probably no other
article of food is more dangerous to health than fish when it shows
even the slightest traces of decomposition. The ability to recognize
the earliest signs of staleness is of the utmost importance. Fish
deteriorate rapidly and should always be carefully inspected before
purchasing.
Fresh fish are firm to the touch, the scales moist and bright, the
gills red, and the eyes clear and slightly prominent. When held flat
in the hand the fish should remain rigid and the head and tail droop
slightly, if at all.
Stale fish are soft and flabby, the skin is dull and the eyes sunken
and often covered with a film. The tendency of the head and tail to
droop is marked and the fish has a characteristic disagreeable odor.
This odor of decomposition is best detected in the gills.
=Lobsters and Crabs.=--These shellfish should always be alive when
purchased. This condition is easily demonstrated by their movements,
and the rule should never be disregarded.
=Oysters and Clams.=--Oysters should not be eaten during the months of
May, June, July, and August; these are their breeding months and they
are unwholesome during that period. That oysters sometimes contain the
germs of typhoid fever is an assured fact; these germs are acquired
not from the natural habitat of the oyster in salt water but from the
fresh-water, so-called "fattening beds," where the oysters are placed
for a season to remove the brackish and salty taste of the sea and to
render them more plump. These beds are frequently subject to
pollution, and the housekeeper should only purchase oysters from
reliable dealers where the purity of the source of the supply is
unquestioned.
Clams are in season and may be eaten throughout the year.
All shellfish when fresh have an agreeable fresh odor. The shells
should be firmly closed or should close when immersed in water and
touched with the finger. If they have been removed from their shells
when purchased, the flesh of the fish itself should be firm, clean in
appearance and not covered with slime or scum; the odor should be
fresh. The odor of dead or decomposed oysters and clams is pungent and
disagreeable.
=MEAT PRODUCTS--Canned or Potted Meats.=--The label on cans containing
meat products should state clearly the exact nature of the contents.
Deception as to the character of the meat is easy to practice and
difficult to detect by any but a trained analyst. The presence of
preservatives can also only be detected by chemical analysis. As these
products are practically all put on the market by the large packing
houses and designed for interstate commerce, they are subject to
government inspection, and, therefore, if they bear the government
stamp may be considered pure. The point that the housekeeper may
consider is the length of time the meat has remained in the can. Put
up under proper precautions these canned goods retain their
wholesomeness for an almost indefinite period. The heads of the cans
should always present a concave surface; if they are convex, it is a
sign of decomposition of the contents. When the can is opened the meat
should have a clean appearance, free from mold or greenish hue, and
the odor should be fresh and not tainted.
=Sausages.=--If possible, sausages should be homemade, then one may be
assured of their purity and freedom from adulteration.
Owing to the rapid color changes and early decomposition of fresh
meat, artificial colors are often used to conceal the former, and
preservatives like boric acid or saltpeter to retard the latter.
The artificial colors, such as carmine and aniline red, may be
detected by observation or by warming the finely divided material on a
water bath with a five per cent solution of sodium salicylate. This
fluid will extract the color, if present.
=Lard.=--Good lard is white and granular and has a firm consistency.
It has an agreeable characteristic odor and taste. The choicest leaf
lard is made from the fat about the kidneys of the hog; the cheaper
grades are made from the fat of the whole animal.
=FRESH VEGETABLES AND FRUITS--Vegetables.=--All green vegetables to be
eaten uncooked should be carefully washed and examined for insects,
dirt, and foreign matter generally. The ova or eggs of the tapeworm
may be ingested with improperly cleaned vegetables. Running water and
a clean brush (kept for this purpose) should be used.
Green vegetables should have a fresh, unwilted appearance; any sign of
staleness or decay should cause their rejection. Overripe or underripe
vegetables are harmful.
Lettuce, celery, and all leaved or stemmed vegetables should be
examined to see if the outer leaves have been removed; this may be
determined by the distance of the leaves from the stem head. The
general signs of disease in vegetables are softening, change of color,
and mold.
The following characteristics indicate fresh and wholesome vegetables:
=Asparagus.=--Firm and white in the stalk with a green, compact tip.
=Beans and Peas= should have green, not yellow, pods, brittle, and
easily snapped open. The vegetable itself should be tender, full and
fleshy, not wrinkled or shrunken.
=Cabbage=, crisp and firm, with a well-rounded and compact head.
=Carrots=, light red or yellow, with a regular, conical shape, sweet
and crisp.
=Cauliflower=, white, compact head; any tinge of yellow or green
generally indicates an inferior quality.
=Celery=, nearly white in color; large, crisp, and solid stalks, nutty
in flavor.
=Cucumbers=, firm, crisp, with a smooth skin and white flesh.
=Lettuce=, the head close and compact; the leaves clean, crisp, and
sweet. When it is too young or running to seed the taste is bitter.
Pale patches on the leaves are caused by mildew and are a sign of
decay.
=Parsnips=, buff in color, with unforked roots, sweet and crisp.
=Potatoes=, underripe, green potatoes are unfit for food; they contain
a poisonous substance which renders them actually harmful. Good
potatoes should have a smooth skin and few eyes; the flesh pale and of
a uniform color and of a firm consistency. A rough skin, with little
depressions, indicates a disease called "scab"; dark-brown patches on
the skin are due to a disease called "smut." Potatoes with such
diseases are of inferior quality. If green on one side, due to
exposure to the sun when growing, the potatoes are unwholesome.
=Fruits.=--Underripe or green fruit should never be eaten. This
condition may be easily detected by the color and consistency of the
fruit. Diseased or decayed fruit is known by its change of color,
softening, and external mold. Spots on fruit are often caused by a
fungus which lowers its quality and renders it less wholesome.
=CEREALS AND THEIR PRODUCTS--Cereals.=--Particularly when bought in
original packages cereals are generally pure and unadulterated. When
bought in bulk there may be found dust, dirt, worms, insects, and
excessive moisture. These may all be determined by careful inspection.
The presence of an undue amount of moisture adds greatly to the weight
of cereals and is therefore a fraud. Cereals should be dry to the
touch and the individual kernels or particles separate and distinct.
=Flour.=--By this general term is meant the ordinary wheat flour. It
should not be too moist, should have a fine white appearance, remain
lumpy, or hold its form, on pressure, not show any particles which
cannot be crushed, and when a handful is thrown against the wall, part
of it should adhere. The odor and taste should be fresh and clean and
not musty or moldy.
The common adulterants are corn and rice meal. If a sample of the
flour be thrown on the surface of a glassful of water, the corn and
rice, being heavier, will sink; grit and sand may be detected in the
same way. If the flour has been adulterated with mineral substances it
may be shown by burning a portion down to an ash; the ash of pure
flour should not exceed two per cent of the total amount; if mineral
substances are present the amount of ash will be greatly increased.
Alum is sometimes added to flour in order to give it a whiter
appearance and to produce whiter and lighter bread; it is most
unwholesome. It can be detected by the so-called "logwood" test, which
is prepared and used as follows:
Make two solutions. The first: a five per cent solution of logwood
chips in alcohol. The second: a fifteen per cent solution of ammonium
carbonate in water. Make a paste of one teaspoonful of the flour and
an equal amount of water; mix with it one-quarter of a teaspoonful of
the logwood solution; follow this immediately with one-quarter of a
teaspoonful of the ammonium carbonate solution. If alum is present,
the paste will show a lavender or blue color; if absent, the mass will
become pink, fading to a dirty brown. If the result is doubtful, set
the paste aside for several hours, when the colors will show more
plainly.
=Bread.=--Bread should be well baked and not too light or too heavy;
the crust should be light brown and adherent to the substance of the
bread. The center should be of even consistency, spongy, and firm; it
should not pit or be soggy or doughy. The pores or holes should be of
practically the same size throughout.
Exceedingly white, light, or porous bread shows the presence of alum.
It may be detected by means of the solutions already mentioned in the
"logwood" test. Mix one teaspoonful of each solution and add three
ounces (six tablespoonfuls) of water; pour this over a lump of bread,
free from crust and about an inch square. After the bread has become
thoroughly soaked, pour off the excess of liquid and dry the bread in
the dish; if alum is present, the mass will show a violet or blue
tint, more marked on drying; if absent, a brownish color will appear.
=Baking Powders.=--Baking powders are of three classes, all having
sodium bicarbonate (baking soda) as their alkaline salt. The first
style is the commonly used and wholesome mixture of cream of tartar
and baking soda; the second has calcium phosphate for the acid salt,
and the third contains alum. All have a certain proportion of starch
to absorb moisture. Of these the alum powders are the most harmful and
should be avoided. Practically all of the well-known brands of baking
powder are of the first-mentioned class and wholesome, and are rarely
adulterated.
=DAIRY PRODUCTS--Milk.=--Pure milk should have a specific gravity of
from 1.027 to 1.033. Its normal reaction is neutral or slightly acid;
it should never be strongly acid. If it is strongly alkaline, i. e.,
turning red litmus paper blue, it is pretty certain that something in
the way of a preservative has been added to it. When left standing for
a few hours the cream should show as a slightly yellowish top layer,
one-tenth or more of the whole amount; the milk below the cream should
be lighter in color and with the slightest bluish tinge. If the color
is of a yellowish tinge throughout, the addition of coloring matter
must be suspected. "Annatto," a vegetable pigment, is used to give a
"rich" tint to milk. To detect it, add one teaspoonful of baking soda
to one quart of milk and immerse in it a strip of unglazed paper; in a
few hours examine the paper; if annatto is present, it will have
become an orange color.[5]
If the whole milk has a blue and thin appearance, or if the cream is
scant in quantity, it has probably been diluted with water. The
popular idea that chalk is sometimes added to poor milk to make it
appear of better quality is erroneous; chalk would always show as a
precipitate, as it does not dissolve, and the presence of such a
sediment would be a too obvious adulteration to be practiced.
Milk should always be kept at a temperature below 50 deg. F.; above that
temperature the bacteria in it multiply with great rapidity and render
it unfit for use.
Milk may be preserved for several days if "pasteurized" or
"sterilized." Pasteurization consists of heating milk to a temperature
of about 167 deg. F., and maintaining it at that degree for twenty
minutes. Sterilization means keeping the milk at a temperature of 212 deg.
F. for two hours and a half. Immediately after either process the milk
should be cooled, then placed in absolutely clean, covered bottles and
kept on ice. These methods are not only harmless but actually
beneficial in that they destroy any disease germs that might be
present.
Chemical preservatives are occasionally found in milk. They may be
suspected if the milk is alkaline in reaction and has a disguised
taste. The ones most commonly used are boric and salicylic acids and
formaldehyde; the two former can only be detected by chemical tests
too delicate and intricate to be used by the housewife. Formaldehyde
may be tested for by using a solution of one drop of a ten per cent
solution of ferric chloride to one ounce of hydrochloric acid.[6] Fill
a small porcelain dish one-third full of this solution; add an equal
volume of milk and heat slowly over a flame nearly to the boiling
point, giving the dish a rotary motion to break up the curd. If
formaldehyde is present, the mass will show a violet color, varying in
depth with the amount present; if it is absent, the mass turns brown.
=Butter.=--Good butter has a fresh, sweet odor and an agreeable taste.
It should be of the same color and consistency throughout, easily cut
and adherent and not crumbly when molded into shapes. Pure butter is
very light in color; nearly all that is sold is colored, in order to
meet the popular demand for "yellow" butter; annatto and other
vegetable and mineral substances are sometimes employed for this
purpose. These coloring matters are generally harmless but may be
detected by dissolving a portion of the butter in alcohol; the natural
color will dissolve, while foreign coloring will not. Butter should
consist of eighty-five per cent fat, with the remainder water,
casein, and salt. The most common methods of adulteration consist in
an excess of water and the addition of oleomargarine. If an excess of
water has been added it may be shown by melting the butter; the water
and fat will separate in two distinct layers. Oleomargarine has a
distinctive meaty smell, like that of cooked meat, and lacks the
characteristic odor of pure butter. If pure butter is melted in a
spoon, it will not sputter; if oleomargarine is present, it will.
The preservatives sometimes used, namely, boric and salicylic acids
and formaldehyde, can only be detected by chemical tests.
=Eggs.=--Two methods may be used to detect stale eggs. First: make a
solution of one part of table salt to ten parts of water and immerse
the suspected egg; if it sinks, it is perfectly fresh; if it remains
in the water below the surface, it is at least three days old, and if
it floats, it is five or more days old.
Second: hold the egg between a bright light and the eye. If it is
fresh, it will show a rosy tint throughout, without dark spots, as the
air chamber is small; if not fresh, it will look cloudy, with many
dark spots present.
=TEA AND COFFEE.=--These substances are extensively adulterated, but
the adulterants are almost without exception harmless.
=Tea.=--The commonest forms of adulteration of tea are as follows:
(_a_) Exhausted tea leaves which have already been used are dried and
added. Their presence may be detected by the weakness of the infusion,
made from a given quantity of the suspected tea, compared with a
similar infusion made from tea known to be pure. (_b_) Leaves from
other plants are sometimes dried and added; these are easily shown if
an infusion is made and when the leaves are thoroughly wet unrolling
and comparing them. (_c_) Green teas may be "faced" or colored with
Prussian blue, indigo, French chalk, or sulphate of lime; black teas
may be similarly treated with plumbago or "Dutch pink." If teas so
treated are shaken up in cold water the coloring matter will wash off.
(_d_) Sand and iron filings are occasionally added for weight;
observation, and the fact that they sink when tea is thrown in water,
will show their presence. Iron filings may be readily found by using a
magnet. (_e_) The presence of starch may be shown by washing the tea
in cold water, straining it, and testing the solution in the following
manner: dissolve one-half teaspoonful of potassium iodide in three
ounces of water and add as much iodine as the solution will dissolve;
a few drops of this solution added to the suspected sample will give a
blue color if starch is present.
=Coffee.=--Coffee should always be purchased in the bean, as ground
coffee is much more frequently adulterated and the foreign substances
are more difficult to detect.
The adulterants commonly used are: chicory, peas, beans, peanuts, and
pellets of roasted wheat flour, rye, corn, or barley.
Fat globules are always present in pure coffee; their presence may be
shown by the fact that imitation coffee sinks in water, while pure
coffee floats.
Chicory is the most frequently used adulterant; it is added for flavor
and to produce a darker infusion, thus giving the impression of
greater strength. It is perfectly harmless and as a drink is actually
preferred by some people. Its detection is comparatively easy. Chicory
grains are dark, gummy, soft, and bitter; coffee grains are hard and
brittle; a small amount put in the mouth will demonstrate the
difference. Chicory will often adhere to the wheels of a coffee
grinder, clogging them on account of its gummy consistency.
When a sample of adulterated coffee is thrown in water the pure coffee
floats and leaves the water unstained; chicory sinks almost instantly,
coloring the water, while peas and beans sink more slowly but also
color the water.
Peas and beans are also detected by the polished appearance of the
broken or crushed grains in marked contrast to the dull surface of
crushed coffee.
The presence of peas, beans, rye, wheat, bread crumbs, and allied
substances may be shown by the fact that they all contain starch.
Make a ten per cent infusion of the suspected coffee; filter it, and
decolorize the solution by boiling it with a piece of animal charcoal.
Test the decolorized solution by slowly adding a few drops of the
"potassium-iodide-iodine solution," directions for preparing which
were given under heading of "Tea." A resulting blue color will
indicate the presence of starch.
=COCOA AND CHOCOLATE.=--The adulterants of these substances are
generally harmless, as they usually consist of flavoring extracts,
sugar, starch, flour, and animal fats. No tests other than flavor,
consistency, and smoothness need be considered. Good cocoa and
chocolate should be slightly bitter, with a pleasant characteristic
odor and taste; they should have a smooth, even consistency and be
free from grit or harsh particles.
=CANNED AND BOTTLED VEGETABLES AND FRUITS.=--In general, acid
substances, such as tomatoes and fruits, should not be canned in tin,
as the action of the acid tends to dissolve the tin. It is better,
therefore, to purchase these articles in glass.
After opening the can the odor and appearance of the contents should
be noted. The odor should be clean and fresh, and the slightest trace
of any sour, musty, or disagreeable smell should cause the rejection
of the food. The appearance should be clean, with no mold; the
consistency and color of the fruit or vegetables should be uniform
throughout. If the color is brighter than that of a similar article
when canned at home, the presence of artificial coloring matter must
be suspected. The brilliant green of some brands of peas, beans, or
Brussels sprouts is produced by the addition of the salts of copper.
This may be proved by leaving the blade of a penknife in the contents
of the can for a short time; if copper is present it will be deposited
on, and discolor, the blade.
Brightly colored fruits should excite suspicion; this same dictum
applies to all brightly colored jams and jellies, as the colors are
usually produced by the addition of carmine or aniline red.
The presence of preservatives, salicylic and boric acids, the
benzoates, etc., can only be proved by delicate chemical tests.
=SUGAR.=--Pure granulated or powdered sugar is white and clean. The
presence of glucose should be suspected in sugar sold below the market
price; it is perfectly harmless, but has a sweetening power of only
about two-thirds that of sugar and is added on account of its
cheapness and to increase the bulk.
If sand, dirt, or flour are present they may be detected by
observation, or by washing the suspected sample in water; flour will
not dissolve, sand will sink, and dirt will discolor the water.
=SPICES.=--Spices should be bought whole and ground in a spice mill as
needed; if this is done, there need be little fear of their impurity,
for whole spices are difficult to simulate or adulterate. Ground
spices may be adulterated with bark, flour, starches, or arrowroot;
these adulterants are harmless, but are fraudulent, as they increase
the bulk and decrease the strength. Their actual presences can only be
demonstrated by a microscopical or chemical examination.
=Peppers.=--Black pepper is made from the whole berry; white pepper is
made from the same berry with the outer husk removed. The adulterants
are usually inert and harmless substances, such as flour, mustard, or
linseed oil; their presence is obviated by the use of the whole
peppercorns, ground as needed.
=Red Pepper.=--This may be adulterated with red lead; when pure it
will be entirely suspended in water; if a sediment falls it is
probably red lead.
=Mustard.=--Practically all of the adulterants of mustard can only be
detected by intricate chemical tests. The presence of turmeric may be
detected by the appearance of an orange-red color when ammonia is
added to a solution of the sample.
=Tomato Catsup.=--Artificial dyestuffs are common, giving a brilliant
crimson or magenta color. Such catsup does not resemble the natural
dull red or brown color of the homemade article.
Preservatives, such as boric, salicylic, or benzoic acids and their
salts, are sometimes added. While their presence cannot be condoned,
yet they are usually present in small amounts and therefore
practically harmless.
=Pickles.=--These should be of a dull-green color. The bright emerald
green sometimes observed is due to the presence of the salts of
copper; this may be proved by dipping the blade of a penknife in the
liquor, as described under the heading of "Canned Goods."
Alum is sometimes used as a preservative and in order to make the
pickles crisp. Its presence may be demonstrated by means of the
"logwood" test mentioned under the heading of "Flour."
=VINEGAR.=--Cider vinegar is of a brownish-yellow color and possesses
a strong odor of apples.
Wine vinegar is light yellow if made from white wine, and red if made
from red wine.
Malt vinegar is brown and has an odor suggestive of sour beer.
Glucose vinegar has the taste and odor of fermented sugar.
Molasses vinegar has the distinctive odor and taste of molasses.
=OLIVE OIL.=--Pure olive oil has a pleasant, bland taste and a
distinctive and agreeable odor, unmistakable in character for that of
any other oil. The finest virgin oil is pale green in color, the
cheaper grades are light yellow.
The adulterants consist of cotton-seed, corn, mustard, and peanut
oils.
When pure olive oil is shaken in a glass or porcelain dish with an
equal quantity of concentrated nitric or sulphuric acid[7] it turns
from a pale to a dark green color in a few minutes; if under this
treatment a reddish to an orange or brown color is produced the
presence of a foreign vegetable oil is to be suspected.
=FLAVORING EXTRACTS--Vanilla.=--This may be wholly or in part the
extract of the Tonka bean or may be made from a chemical substance
known as vanillin. The best practical working tests as to its purity
are the price, taste, and odor. The distinctive odor and taste of
vanilla are characteristic and cannot be mistaken.[8]
=Lemon.=--This extract is often made from tartaric or citric acid.
They may be tested for as follows: to a portion of the extract in a
test tube add an equal volume of water to precipitate the oil; filter,
and add one or two drops of the filtrate to a test tube full of cold,
clear limewater; if tartaric acid is present a precipitate will fall
to the bottom of the tube. Filter off this precipitate (if present)
and heat the contents of the tube; if citric acid is present it will
precipitate in the hot limewater.
FOOTNOTE.--Dr. Baker wishes to acknowledge her indebtedness to the
following authorities and the volumes mentioned for many helpful
suggestions. Pearman and Moore, "Aids to the Analysis of Foods and
Drugs"; Albert E. Leach, "Food Inspection and Analysis"; Francis
Vacher, "Food Inspector's Hand Book."
FOOTNOTES:
[4] The presence of aniline dyes may be detected by mixing a portion
of the suspected sample with enough water to make a thin paste. Wet a
piece of white wool cloth or yarn thoroughly with water and place it
with the paste in an agate saucepan. Boil for ten minutes, stirring
frequently. If a dye has been used the wool will be brightly colored;
a brownish or pinkish color indicates the natural coloring matter of
the fruit or vegetable.--EDITOR.
[5] A little vinegar added to heated cream or milk produces in the
curd a distinct orange color if an aniline dye has been used to make
the cream look "rich." The curd will be brown if annatto or caromel
has been used. If pure, the curd will be white.--EDITOR.
[6] This acid must be used with great care; no portion of it should
ever come in contact with the skin or clothing.
[7] These acids must be used with great care. They should never be
allowed to come in contact with the skin or clothing.
[8] Add a little sugar-of-lead solution to the suspected extract; true
vanilla extract will give a yellowish-brown precipitate and a pale,
straw-colored liquid. If the extract is artificial, the addition of
the lead solution will have little or no effect.--EDITOR.
CHAPTER II
=Mushroom Poisoning=
_Symptoms--Treatment--How to Tell Mushrooms--The Common Kind--Other
Varieties--The Edible Puffball--Poisonous Mushrooms Frequently
Mistaken._
=MUSHROOM POISONING.=--Vomiting, cramps, diarrhea, pains in legs;
possibly confusion, as if drunk, stupidity, followed by excitement,
and perhaps convulsions. Lips and face may be blue. Pulse may be weak.
_First Aid Rule 1.--Rid the stomach and bowels of remaining poison.
Give emetic of mustard, tablespoonful in three glasses of warm water,
unless vomiting is already excessive. When vomiting ceases, give
tablespoonful of castor oil, or compound cathartic pill._ GIVE NO
SALTS. _Also empty bowels with injection of tablespoonful of glycerin
in pint of warm soapsuds and water._
_Rule 2.--Antidote the poison. Give a cup of strong coffee and fifteen
drops of tincture of belladonna to adult. Repeat both once, after two
hours have passed._
_Rule 3.--Rest and stimulate. Put patient to bed. Give whisky, a
tablespoonful in twice as much water. Give tincture of digitalis, ten
drops every two hours, till two or three doses are taken by adult._
=Symptoms.=--Vomiting and diarrhea come on in a few hours to half a
day, with cramps in the stomach and legs. The face and lips may grow
blue. There is great prostration. In the case of poisoning by the _fly
amanita_, stupor may appear early, the patient acting as if drunk, and
difficult breathing may be a noticeable symptom. Afterwards the
patient becomes excited and convulsions develop. The pulse becomes
weak and slow. The patient may die in a few hours, or may linger for
three or four days. If treatment be thorough, recovery may result.
=Treatment.=--Unless vomiting has already been excessive, the patient
should receive a tablespoonful of mustard mixed with a glassful of
tepid water. After the vomiting ceases he should receive a
tablespoonful of castor oil, or any cathartic except salts. If the
cathartic is vomited, he should receive an injection into the rectum
of a tablespoonful of glycerin mixed with a pint of soapsuds and
water. Coffee and atropine (or belladonna) are the best antidotes.
If a physician be secured, he will probably give a hypodermic
injection of atropine. If a physician is not procurable, the patient
should receive a cup of strong coffee, and a dose of ten or fifteen
drops of tincture of belladonna in a tablespoonful of water, if an
adult. This dose should be repeated once after the lapse of two hours.
The patient should be kept in bed, a bedpan being used when the bowels
move.
When the pulse begins to grow weak, two tablespoonfuls of whisky and
ten drops of the tincture of digitalis should be given to an adult in
quarter of a glass of hot water. The digitalis should be repeated
every two hours till three or four doses have been taken. The patient
must be kept warm with hot-water bottles and blankets.
=HOW TO KNOW MUSHROOMS.=--One-sixth of one of the poisonous mushrooms
has caused death. It is, therefore, impossible to exert too much care
in selecting them for food. A novice would much better learn all the
characteristics of edible and poisonous mushrooms in the field from an
expert before attempting to gather them himself, and should not trust
to book descriptions, except in the case of the few edible species
described hereafter. It is not safe for a novice to gather the
immature or button mushrooms, because it is much more difficult to
determine their characteristics than those of the full grown. As
reference books, the reader is advised to procure Bulletin No. 15 of
the United States Department of Agriculture, entitled "Some Edible and
Poisonous Fungi," by Dr. W. G. Farlow, which will be sent without
charge on request by the Agricultural Department at Washington;
"Studies of American Fungi," by Atkinson, and Miss Marshall's
"Mushroom Book," all of which are fully illustrated, and will prove
helpful to those interested in edible fungi.
There are no single tests by which one can distinguish edible from
poisonous fungi, such as taste, odor, the blackening of a silver
spoon, etc., although contrary statements have been made. Even when
the proper mushrooms have been eaten, ill effects, death itself, may
follow if the mushrooms have been kept too long, have been
insufficiently cooked, have been eaten in too large a quantity
(especially by children), or if the consumer is the possessor of an
unhappy idiosyncrasy toward mushrooms.
No botanic distinction exists between toadstools and mushrooms;
mushrooms may be regarded as edible toadstools. They are all,
botanically speaking, edible or poisonous fungi. A description follows
of the five kinds of fungi most commonly eaten, and the poisonous
species which may be mistaken for them.
=EDIBLE MUSHROOMS.=--=1. The Common Mushroom= (_Agaricus
Campestris_).--The fungi called agarici are those which have gills,
that is, little plates which look like knife blades on the under
surface of the top of the mushroom, radiating outward from the stem
like the spokes of a wheel. This is the species most frequently grown
artificially, and sold in the markets. The top or cap of this mushroom
is white, or of varying shades of brown, and measures from one and a
half to three or even four inches in diameter. It is found in the
latter part of August, in September, and in October, growing in
clusters on pastures, fields, and lawns.
The gills are pink or salmon colored in the newly expanded specimen;
but as it grows older, or after it is picked, the gills turn dark
purple, chestnut brown, or black. This is the important point to
remember, since the poisonous species mistaken for it all have white
gills. The gills end with abrupt upward curves at the center of the
cap without being attached to the stem. In the young mushroom, when
the cap is folded down about the stem, the gills are not noticeable,
as they are covered by a veil or filmy membrane, a part of which
remains attached to the stem (when the top expands), as a ring or
collar about the stem a little more than halfway up from the ground.
The stem is solid and not hollow, and there is no bulbous enlargement
at the base of the stem, surrounded by scales or a collar, as occurs
in the _fly amanita_ and other poisonous species. Neither the
_campestris_ nor any other mushroom should be eaten when over a day
old, since decomposition quickly sets in.
[Illustration: FIG. 35.
THE FIELD MUSHROOM.
(_Agaricus Campestris._)
An edible variety; very common.]
=2. Horse Mushroom= (_Agaricus Arvensis_).--This species may be
considered with the foregoing, but it differs in being considerably
larger (measuring four to ten inches across) and in having a more
shiny cap, of a white or brown hue. The ring about the stem is
noticeably wider and thicker, and is composed of two distinct layers.
The gills are white at first, turning dark brown comparatively late,
and the stem is a little hollow as it matures. In some localities it
is more common than the _campestris_ in fields and pastures, while in
other places it is found only in rich gardens, about hot beds, or in
cold frames. It is not distinguished from the _campestris_ by market
people, but is often sold with the latter.
[Illustration: FIG. 36.
THE HORSE MUSHROOM.
(_Agaricus Arvensis._)
This variety is edible.]
=3. Shaggy Mane, Ink Cap, or Horsetail Fungus= (_Coprinus
Comatus_).--This mushroom possesses the most marked characteristics of
any of the edible species; it would seem impossible to mistake its
identity from written descriptions and illustrations. It is considered
by many superior in flavor to the _campestris_.
The top or cap does not expand in this mushroom, until it begins to
turn black, but remains folded down about the stem like a closed
umbrella. Mature specimens are usually three to five, occasionally
from eight to ten, inches high. The stem is hollow. The inside of the
cap or gills and the stem are snow white. The outer surface of the
cap, which is white in young plants, becomes of a faint, yellow-brown
or tawny color in mature specimens, and also darker at the top.
Delicate scales often rolled up at their lower ends are seen on the
exterior of the cap, more readily in mature mushrooms, hence the name
"shaggy mane." There is a ring around the stem at the lower margin of
the cap, and it is so loosely attached to either the cap or stem that
it sometimes drops down to the base of the latter.
The most salient feature of shaggy mane is the change which occurs
when it is about a day old; it turns black and dissolves away into an
inky fluid, whence the other common name "ink cap." The mushroom
should not be eaten when in this condition. The ink cap is usually
found growing in autumn, rarely in summer, in richer earth than the
common mushroom. One finds it in heaps of street scrapings, by
roadsides, in rich lawns, in soils filled with decomposing wood and in
low, shaded, moist grounds.
[Illustration: FIG. 37.
THE HORSE-TAIL FUNGUS.
(_Coprinus Comatus._)
Edible; cut shows entire plant and section.]
=4. Fairy-ring Mushroom= (_Marasmius Oreades_).--This species usually
grows on lawns, in clusters which form an imperfect circle or
crescent. The ring increases in size each year as new fungi grow on
the outside, while old ones toward the center of the circle perish.
This mushroom is small and slender, and rarely exceeds two inches in
breadth. The cap and the tough and tubular stem are buff, and the
gills, few in number and bulging out in the middle, are of a lighter
shade of the same color. There is no ring about the stem. Several
crops of the fairy-ring mushroom are produced all through the season,
but the most prolific growth appears after the late fall rains. There
are other fungi forming rings, some of which are poisonous, and they
may not be easily distinguished from the edible species; hence great
care is essential in gathering them. The under surface of the cap is
brown or blackish in the mature plants of poisonous species.
[Illustration: FIG. 38.
THE FAIRY-RING MUSHROOM.
(_Marasmius Oreades._)
An edible variety.]
=5. Edible Puffball= (_Lycoperdon Cyathiforme_).--Edible puffballs
grow in open pastures, and on lawns and grassplots, often forming
rings. They are spherical in form, generally from one and a half to
two inches, occasionally six inches, in diameter, broad and somewhat
flattened at the top, and tapering at the base, white or brown
outside. They often present an irregularly checkered appearance, owing
to the fact that the white interior shows between the dark raised
parts. The interior is at first pure white and of solid consistency,
but later becomes softer and yellowish, and then contains an
amber-colored juice. After the puffball has matured, the contents
change into a brown, dustlike mass, and the top falls off; and it is
then inedible. All varieties of puffball with a pure white interior
are harmless, if eaten before becoming crumbly and powdery. There is
only one species thought to be poisonous, and that has a yellow-brown
exterior, while the interior is purple-black, marbled with white.
[Illustration: FIG. 39.
THE EDIBLE PUFFBALL.
(_Lycoperdon Cyathiforme._)
Upper illustration shows entire plant; lower, a section.]
=POISONOUS MUSHROOMS FREQUENTLY MISTAKEN.=
_To escape eating poisonous mushrooms do not gather the buttons, and
be suspicious of those growing in woods and shady spots that show any
bright hue, or have a scaly or dotted cap, or white gills.[9] By so
doing the following species will be avoided._
=Fly Amanita= (_Amanita Muscaria_).--Infusions of this mushroom made
by boiling in water are used to kill flies. This species grows in
woods and shady places, by roadsides, and along the borders of fields,
and is much commoner than the _campestris_ in some localities. It
prefers a poor, gravelly soil, and is found in summer.
The stem is hollow and its gills are white. The cap is variously
colored, white, orange, yellow, or even brilliant red, and dotted over
with corklike particles or warty scales which are easily rubbed off.
There is a large, drooping collar about the upper part of the hollow,
white stem, and the latter is scaly below with a bulbous enlargement
at its base.
The young mushrooms, or buttons, do not exhibit the dotted cap, and
the bulbous scaly base may be left in the ground when the mushroom is
picked. The _fly amanita_ is usually larger than the common mushroom.
[Illustration: FIG. 40.
A POISONOUS FUNGUS.
(_Amanita Muscaria._)
The Fly Agaric.]
=Death Cup or Deadly Agaric= (_Amanita Phalloides_).--This species is
more fatal in its effects than the preceding. Its salient feature is a
bulbous base surmounted and surrounded by a collar or cup out of which
the stem grows. This is often buried beneath the ground, however, so
that it may escape notice. The gills and stem are white like the
preceding, but the cap is usually not dotted but glossy, white,
greenish, or yellow. There is also a broad, noticeable ring about the
stem, as in the _fly amanita_. This mushroom frequents moist, shady
spots, also along the borders of fields. It occurs singly, and rarely
in fields or pastures.
[Illustration: FIG. 41.
THE DEADLY AGARIC.
(_Amanita Phalloides._)
This variety is very poisonous.]
FOOTNOTES:
[9] The shaggy mane has white gills, but its other features are
characteristic.
Part III
THE HOUSE AND GROUNDS
BY
GEORGE M. PRICE
_Acknowledgment_
We beg to tender grateful acknowledgment to author and publisher for
the use of Dr. George M. Price's valuable articles on sanitation. The
following extracts are taken from Dr. Price's "Handbook on
Sanitation," published by John Wiley & Son, and are covered by
copyright.
CHAPTER I
=Soil and Sites=
=Definition.=--By the term "soil" we mean the superficial layer of the
earth, a result of the geological disintegration of the primitive rock
by the action of the elements upon it and of the decay of vegetable
and animal life.
=Composition.=--Soil consists of solids, water, and air.
=Solids.=--The solid constituents of the soil are inorganic and
organic in character.
The inorganic constituents are the various minerals and elements found
alone, or in combination, in the earth, such as silica, aluminum,
calcium, iron, carbon, sodium, chlorine, potassium, etc.
The characteristics of the soil depend upon its constituents, and upon
the predominance of one or the other of its composing elements. The
nature of the soil also depends upon its physical properties. When the
disintegrated rock consists of quite large particles, the soil is
called a _gravel soil_. A _sandy soil_ is one in which the particles
are very small. _Sandstone_ is consolidated sand. _Clay_ is soil
consisting principally of aluminum silicate; in _chalk_, soft calcium
carbonate predominates.
The organic constituents of the soil are the result of vegetable and
animal growth and decomposition in the soil.
=Ground Water.=--Ground water is that continuous body or sheet of
water formed by the complete filling and saturation of the soil to a
certain level by rain water; it is that stratum of subterranean lakes
and rivers, filled up with alluvium, which we reach at a higher or
lower level when we dig wells.
The level of the ground water depends upon the underlying strata, and
also upon the movements of the subterranean water bed. The relative
position of the impermeable underlying strata varies in its distance
from the surface soil. In marshy land the ground water is at the
surface; in other places it can be reached only by deep borings. The
source of the ground water is the rainfall, part of which drains into
the porous soil until it reaches an impermeable stratum, where it
collects.
The movements of the ground water are in two directions--horizontal
and vertical. The horizontal or lateral movement is toward the seas
and adjacent water courses, and is determined by hydrostatic laws and
topographical relations. The vertical motion of the ground water is to
and from the surface, and is due to the amount of rainfall, the
pressure of tides, and water courses into which the ground water
drains. The vertical variations of the ground water determine the
distance of its surface level from the soil surface, and are divided
into a persistently low-water level, about fifteen feet from the
surface; a persistently high-water level, about five feet from the
surface, and a fluctuating level, sometimes high, sometimes low.
=Ground Air.=--Except in the hardest granite rocks and in soil
completely filled with water the interstices of the soil are filled
with a continuation of atmospheric air, the amount depending on the
degree of porosity of the soil. The nature of the ground air differs
from that of the atmosphere only as it is influenced by its location.
The principal constituents of the air--nitrogen, oxygen, and carbonic
acid--are also found in the ground air, but in the latter the relative
quantities of O and CO2 are different.
AVERAGE COMPOSITION OF ATMOSPHERIC AIR IN 100 VOLUMES
Nitrogen 79.00 per cent.
Oxygen 20.96 "
Carbonic acid 0.04 "
AVERAGE COMPOSITION OF GROUND AIR
Nitrogen 79.00 per cent.
Oxygen 10.35 "
Carbonic acid 9.74 "
Of course, these quantities are not constant, but vary in different
soils, and at different depths, times, etc. The greater quantity of
CO2 in ground air is due to the process of oxidation and decomposition
taking place in the soil. Ground air also contains a large quantity
of bacterial and other organic matter found in the soil.
Ground air is in constant motion, its movements depending upon a great
many factors, some among these being the winds and movements of the
atmospheric air, the temperature of the soil, the surface temperature,
the pressure from the ground water from below, and surface and rain
water from above, etc.
=Ground Moisture.=--The interstices of the soil above the ground-water
level are filled with air _only_, when the soil is absolutely dry; but
as such a soil is very rare, all soils being more or less damp, soil
usually contains a mixture of air and water, or what is called _ground
moisture_.
Ground moisture is derived partly from the evaporation of the ground
water and its capillary absorption by the surface soil, and partly by
the retention of water from rains upon the surface. The power of the
soil to absorb and retain moisture varies according to the physical
and chemical, as well as the thermal, properties of the soil.
Loose sand may hold about 2 gallons of water per cubic foot; granite
takes up about 4 per cent of moisture; chalk about 15 per cent; clay
about 20 per cent; sandy loam 33 to 35 per cent; humus[10] about 40
per cent.
=Ground Temperature.=--The temperature of the soil is due to the
direct rays of the sun, the physicochemical changes in its interior,
and to the internal heat of the earth.
The ground temperature varies according to the annual and diurnal
changes of the external temperature; also according to the character
of the soil, its color, composition, depth, degree of organic
oxidation, ground-water level, and degree of dampness. In hot weather
the surface soil is cooler, and the subsurface soil still more so,
than the surrounding air; in cold weather the opposite is the case.
The contact of the cool soil with the warm surface air on summer
evenings is what produces the condensation of air moisture which we
call dew.
=Bacteria.=--Quite a large number of bacteria are found in the soil,
especially near the surface, where chemical and organic changes are
most active. From 200,000 to 1,000,000 bacteria have been found in 1
c.c. of earth. The ground bacteria are divided into two
groups--saprophytic and pathogenic. The saprophytic bacteria are the
bacteria of decay, putrefaction, and fermentation. It is to their
benevolent action that vegetable and animal _debris_ is decomposed,
oxidized, and reduced to its elements. To these bacteria the soil owes
its self-purifying capacity and the faculty of disintegrating animal
and vegetable _debris_.
The pathogenic bacteria are either those formed during the process of
organic decay, and which, introduced into the human system, are
capable of producing various diseases, or those which become lodged in
the soil through the contamination of the latter by ground water and
air, and which find in the soil a favorable lodging ground, until
forced out of the soil by the movements of the ground water and air.
=Contamination of the Soil.=--The natural capacity of the soil to
decompose and reduce organic matter is sometimes taxed to its utmost
by the introduction into the soil of extraneous matters in quantities
which the soil is unable to oxidize in a given period. This is called
contamination or pollution of soil, and is due: (1) to surface
pollution by refuse, garbage, animal and human excreta; (2) to
interment of dead bodies of beasts and men; (3) to the introduction of
foreign deleterious gases, etc.[11]
_Pollution by Surface Refuse and Sewage._--This occurs where a large
number of people congregate, as in cities, towns, etc., and very
seriously contaminates the ground by the surcharge of the surface soil
with sewage matter, saturating the ground with it, polluting the
ground water from which the drinking water is derived, and increasing
the putrefactive changes taking place in the soil. Here the pathogenic
bacteria abound, and, by multiplying, exert a very marked influence
upon the health by the possible spread of infectious diseases. Sewage
pollution of the soils and of the source of water supply is a matter
of grave importance, and is one of the chief factors of high
mortality in cities and towns.
_Interment of Bodies._--The second cause of soil contamination is also
of great importance. Owing to the intense physicochemical and organic
changes taking place within the soil, all dead animal matter interred
therein is easily disposed of in a certain time, being reduced to the
primary constituents, viz., ammonia, nitrous acid, carbonic acid,
sulphureted and carbureted hydrogen, etc. But whenever the number of
interred bodies is too great, and the products of decomposition are
allowed to accumulate to a very great degree, until the capacity of
the soil to absorb and oxidize them is overtaxed, the soil, and the
air and water therein, are polluted by the noxious poisons produced by
the processes of decomposition.
_Introduction of Various Foreign Materials and Gases._--In cities and
towns various pipes are laid in the ground for conducting certain
substances, as illuminating gas, fuel, coal gas, etc.; the pipes at
times are defective, allowing leakage therefrom, and permitting the
saturation of the soil with poisonous gases which are frequently drawn
up by the various currents of ground air into the open air and
adjacent dwellings.
=Influence of the Soil on Health.=--The intimate relations existing
between the soil upon which we live and our health, and the marked
influence of the soil on the life and well-being of man, have been
recognized from time immemorial.
The influence of the soil upon health is due to: (1) the physical and
chemical character of the soil; (2) the ground-water level and degree
of dampness; (3) the organic impurities and contamination of the soil.
The physical and chemical nature of the soil, irrespective of its
water, moisture, and air, has been regarded by some authorities as
having an effect on the health, growth, and constitution of man. The
peculiar disease called cretinism, as well as goitre, has been
attributed to a predominance of certain chemicals in the soil.
The ground-water level is of great importance to the well-being of
man. Professor Pettenkofer claimed that a persistently low water level
(about fifteen feet from the surface) is healthy, the mortality being
the lowest in such places; a persistently high ground-water level
(about five feet from the surface) is unhealthy; and a fluctuating
level, varying from high to low, is the most unhealthy, and is
dangerous to life and health. Many authorities have sought to
demonstrate the intimate relations between a high water level in the
soil and various diseases.
A damp soil, viz., a soil wherein the ground moisture is very great
and persistent, has been found inimical to the health of the
inhabitants, predisposing them to various diseases by the direct
effects of the dampness itself, and by the greater proneness of damp
ground to become contaminated with various pathogenic bacteria and
organisms which may be drawn into the dwellings by the movements of
the ground air. As a rule, there is very little to hinder the ground
air from penetrating the dwellings of man, air being drawn in through
cellars by changes in temperature, and by the artificial heating of
houses.
The organic impurities and bacteria found in the soil are especially
abundant in large cities, and are a cause of the evil influence of
soil upon health. The impurities are allowed to drain into the ground,
to pollute the ground water and the source of water supply, and to
poison the ground air, loading it with bacteria and products of
putrefaction, thus contaminating the air and water so necessary to
life.
=Diseases Due to Soil.=--A great many diseases have been thought to be
due to the influence of the soil. An aetiological relation had been
sought between soil and the following diseases: malaria, paroxysmal
fevers, tuberculosis, neuralgias, cholera, yellow fever, bubonic
plague, typhoid, dysentery, goitre and cretinism, tetanus, anthrax,
malignant Oedema, septicaemia, etc.
=Sites.=--From what we have already learned about the soil, it is
evident that it is a matter of great importance as to where the site
for a human habitation is selected, for upon the proper selection of
the site depend the health, well-being, and longevity of the
inhabitants. The requisite characteristics of a healthy site for
dwellings are: a dry, porous, permeable soil; a low and nonfluctuating
ground-water level, and a soil retaining very little dampness, free
from organic impurities, and the ground water of which is well drained
into distant water courses, while its ground air is uncontaminated by
pathogenic bacteria. Exposure to sunlight, and free circulation of
air, are also requisite.
According to Parkes, the soils in the order of their fitness for
building purposes are as follows: (1) primitive rock; (2) gravel, with
pervious soil; (3) sandstone; (4) limestone; (5) sandstone, with
impervious subsoil; (6) clays and marls; (7) marshy land, and (8) made
soils.
It is very seldom, however, that a soil can be secured having all the
requisites of a healthy site. In smaller places, as well as in cities,
commercial and other reasons frequently compel the acquisition of and
building upon a site not fit for the purpose; it then becomes a
sanitary problem how to remedy the defects and make the soil suitable
for habitation.
=Prevention of the Bad Effects of the Soil on Health.=--The methods
taught by sanitary science to improve a defective soil and to prepare
a healthy site are the following:
(1) Street paving and tree planting.
(2) Proper construction of houses.
(3) Subsoil drainage.
_Street Paving_ serves a double sanitary purpose. It prevents street
refuse and sewage from penetrating the ground and contaminating the
surface soil, and it acts as a barrier to the free ascension of
deleterious ground air.[12]
_Tree Planting_ serves as a factor in absorbing the ground moisture
and in oxidizing organic impurities.
_The Proper Construction of the House_ has for its purpose the
prevention of the entrance of ground moisture and air inside the house
by building the foundations and cellar in such a manner as to entirely
cut off communication between the ground and the dwelling. This is
accomplished by putting under the foundation a solid bed of concrete,
and under the foundation walls damp-proof courses.
The following are the methods recommended by the New York City
Tenement House Department for the water-proofing and damp-proofing of
foundation walls and cellars:
_Water-proofing and Damp-proofing of Foundation Walls._--"There shall
be built in with the foundation walls, at a level of six (6) inches
below the finished floor level, a course of damp-proofing consisting
of not less than two (2) ply of tarred felt (not less than fifteen
(15) pounds weight per one hundred (100) square feet), and one (1) ply
of burlap, laid in alternate layers, having the burlap placed between
the felt, and all laid in hot, heavy coal-tar pitch, or liquid
asphalt, and projecting six (6) inches inside and six (6) inches
outside of the walls.
"There shall be constructed on the outside surface of the walls a
water-proofing lapping on to the damp-proof course in the foundation
walls and extending up to the soil level. This water-proofing shall
consist of not less than two (2) ply of tarred felt (of weight
specified above), laid in hot, heavy coal-tar pitch, or liquid
asphalt, finished with a flow of hot pitch of the same character. This
water-proofing to be well stuck to the damp course in the foundation
walls. The layers of felt must break joints."
_Water-proofing and Damp-proofing of Cellar Floors._--"There shall be
laid, above a suitable bed of rough concrete, a course of
water-proofing consisting of not less than three (3) ply of tarred
felt (not less than fifteen (15) pounds weight per one hundred (100)
square feet), laid in hot, heavy coal-tar pitch, or liquid asphalt,
finished with a flow of hot pitch of the same character. The felt is
to be laid so that each layer laps two-thirds of its width over the
layer immediately below, the contact surface being thoroughly coated
with the hot pitch over its entire area before placing the upper
layer. The water-proofing course must be properly lapped on and
secured to the damp course in the foundation walls."
Other methods of damp-proofing foundations and cellars consist in the
use of slate or sheet lead instead of tar and tarred paper. An
additional means of preventing water and dampness from coming into
houses has been proposed in the so-called "dry areas," which are open
spaces four to eight feet wide between the house proper and the
surrounding ground, the open spaces running as deep as the foundation,
if possible. The dry areas are certainly a good preventive against
dampness coming from the sides of the house.
[Illustration: FIG. 4.
CONCRETE FOUNDATION AND DAMP-PROOF COURSE.]
_Subsoil Drainage._--By subsoil drainage is meant the reducing of the
level of the ground water by draining all subsoil water into certain
water courses, either artificial or natural. Subsoil drainage is not a
modern discovery, as it was used in many ancient lands, and was
extensively employed in ancient Rome, the valleys and suburbs of which
would have been uninhabitable but for the draining of the marshes by
the so-called "_cloacae_" or drains, which lowered the ground-water
level of the low parts of the city and made them fit to build upon.
The drains for the conduction of subsoil water are placed at a
certain depth, with a fall toward the exit. The materials for the
drain are either stone and gravel trenches, or, better, porous
earthenware pipes or ordinary drain tile. The drains must not be
impermeable or closed, and sewers are not to be used for drainage
purposes. Sometimes open, V-shaped pipes are laid under the regular
sewers, if these are at the proper depth.
By subsoil drainage it is possible to lower the level of ground water
wherever it is near or at the surface, as in swamps, marsh, and other
lands, and prepare lands previously uninhabitable for healthy sites.
FOOTNOTES:
[10] Humus is vegetable mold; swamp muck; peat; etc.--EDITOR.
[11] A leak in a gas main, allowing the gas to penetrate the soil,
will destroy trees, shrubbery, or any other vegetation with which it
comes in contact.--EDITOR.
[12] Town and village paving plans will benefit by knowledge of the
recent satisfactory experience of New York City authorities in paving
with wood blocks soaked in a preparation of creosote and resin. As
compared with the other two general classes of paving, granite blocks,
and asphalt, these wood blocks are now considered superior.
The granite blocks are now nearly discarded in New York because of
their permeability, expense, and noise, being now used for heavy
traffic only.
Asphalt is noiseless and impermeable (thereby serving the "double
sanitary purpose" mentioned by Dr. Price).
But the wood possesses these qualities, and has in addition the
advantage of inexpensiveness, since it is more durable, not cracking
at winter cold and melting under summer heat like the asphalt; and
there is but slight cost for repairs, which are easily made by taking
out the separate blocks.
These "creo-resinate" wood blocks, recently used on lower Broadway,
Park Place, and the congested side streets, are giving admirable
results.--EDITOR.