Total organic elements to .2 .2 to .4 Over .4
Oxygen required to .15 .15 to .2 " .2
Albuminoid ammonia to .010 .010 to .015 " .015
{185} In connection with impure water should be mentioned impure ice.
Ice is purer than the water from which it forms, but if cut on a foul
pond it will itself be foul, and the vitality of some microscopic
organisms is not destroyed by their being frozen, as is shown by the
fact that samples from the centre of blocks of ice will inoculate
sterilized infusions with the germs of putrefaction, precisely as the
water of which the ice is composed would have done before it was
frozen. Disease has been traced to impure ice, and it may be that it
is more frequently due to this cause than has heretofore been
supposed; at all events, it is well to bear the possibility in mind.
The subject of impure water will be further considered in speaking of
habitations.
IV. CLIMATE.--The literature of the effects of different climates upon
the human body is very extensive, following the general rule that the
less positive or precise knowledge there is upon a given subject the
more will be written about it. Of all animals, man seems to adapt
himself most readily to the extremes of climate; and, although it is
commonly supposed that a tropical climate is injurious to those coming
from cooler regions, yet it has been found that where he takes the
same precautions to ensure cleanliness, pure water and air, and proper
food, the European does not have a higher rate of mortality in Algeria
or in the East or West Indies than he does at home, if the effects of
cholera and yellow fever be excepted.
Dr. Parkes defines the effect of climate upon the human body to be
"the sum of the influences which are connected with the solar
agencies, the soil, the air, or the water of a place;" in other words,
he makes it nearly equivalent to the locality or the environment. By
"climate" we understand, commonly, the sum of meteorological
influences, the most important of which, as regards health, are
temperature, humidity, and wind. The effects of temperature in
producing disease are often confounded with the effects of change of
temperature, which last is perhaps the more important of the two, and
should be specially borne in mind in advising climato-therapy for
chronic or wasting diseases.
The influence of climate in causing disease, although well known for
over two thousand years, has not led to much effort to avoid or
prevent effects which are accepted as inevitable by the great
majority. It is true that in the effort to secure physical comfort by
houses, clothing, artificial heat, and the like, much hygienic work
has been done, and the steadily increasing tendency on the part of all
who can afford it to seek rest and comfort at the seaside or in the
mountains during hot weather is no doubt due, in part, to the fact
that experience has shown that the money expended in thus securing
health and strength is a good investment. It is unfortunate that
"health resorts," so called, do not always prove to be such: they
become fashionable, overcrowded; the arrangements for the disposal of
excreta are cheap makeshifts, leading to soil- and water-pollution,
until finally an epidemic of diarrhoea or typhoid fever occurs, with
the usual results.
The consideration of climate as a therapeutic agent belongs with the
articles relating to the several diseases to which it is applicable.
The great desideratum wherewith to place this subject upon a
scientific and practical basis is a system of reliable returns of the
deaths, and if possible of {186} certain diseases, throughout the
country, and especially at those points most in vogue as health
resorts.
V. HABITATIONS.--That a man's health depends very much on the
character, condition, and location of his dwelling-place is now so
generally admitted that in many cases where a physician is called in
he will be asked whether he thinks the disease has been caused by any
peculiarity about the house or the bedroom of the patient. And a
careful examination will usually discover in one of them several evils
to be remedied, although their connection with the case in hand may be
very doubtful. There are very few homes properly constructed from a
sanitary point of view; and, although we may not agree with Dr.
Wilson, that "the modern prison is in all sanitary essentials the best
existing type of what a healthy dwelling ought to be," it is
nevertheless certain that the health of the inmates is much more
carefully consulted in planning a penitentiary than it usually is in
planning a college, a hotel, or a dwelling-house. Matters are
gradually improving in this respect: the worst of the tenement-house
rookeries and fever-nests in most of our large cities have been
improved or abolished, and our wealthier citizens are beginning to pay
some attention to their house-drainage as well as to the pattern of
their mantelpieces. But the great majority of men are still careless
and negligent as to the sanitary condition of their homes, and
probably two physicians out of three live in houses in which numerous
defects would be pointed out by a sanitary engineer--defects of which
they are themselves more or less aware. The majority of people in our
large cities under existing conditions cannot afford to have healthy
houses, and the great causes of the excessive mortality, and brevity
of life, in all such cities, are poverty and overcrowding, the latter
resulting from the former. The problem as to the best mode of
improving the sanitary condition of the tenement-house population does
not, however, come before the practising physician for special
consideration, and need not be considered here. Nor is the physician
liable to be consulted with regard to the sufficiency, from a sanitary
point of view, of the plan of a house yet to be built, although he
will occasionally be asked as to the healthfulness of a proposed site.
The questions which he will be asked are such as the following: "Is
the cause of this particular case of disease in the house, or
connected with it? and if so, what is it?"--"Do you think this is a
healthy house?"--"Is the location a healthy one?"--"Is it necessary
that I should give up this house to preserve the lives and health of
my children?" While it is, of course, often impossible to answer with
precision such questions as these, an answer of some kind must be
given; and this should not be a mere random guess, but based on a
deliberate estimate of the probabilities in the case. The
healthfulness of a house is to be judged of, in part, from its
history, if it be possible to obtain any; in part, from such facts as
can be discovered by a careful examination of the premises and
vicinity. The sanitary history of a house is the history of the
diseases and deaths which have occurred in it, together with a set of
plans showing the precise location and character of the house-drainage
and of its fresh-air supply. Such a record is in most cases,
unfortunately, not attainable, although to a person proposing to buy
or rent a house it would often be quite as important as a record of
title. In a well-organized health-office it should be possible to
ascertain the number and causes of the deaths which have {187}
occurred in any given house or square in the city, and also the
character and location of its drainage and sewer connections. Such
records are especially valuable in an investigation of an outbreak of
disease in a community.
The sanitary inspection of a house includes the site and the building
itself. The character of the site is mainly determined by its dryness,
by the presence or absence of organic matter in the soil, and by its
porosity taken in connection with the character of the vicinity.
One-third of the volume of some soils consists of air, and all dry
soils and rocks contain a much larger quantity of air than is commonly
supposed. The influence of soil upon health is exerted mainly through
the media of water and air, but it also affects temperature and
vegetation, being an important factor in climate. Residence on a damp
soil has a tendency to produce diseases of the lungs, and especially
phthisis; but how it does this is unknown, though it would be easy to
construct a plausible theory in connection with the supposed causation
of phthisis by a bacillus. The practical point for the physician is,
that the prevalence of phthisis in a locality, even if it be so
limited as to comprise but a single house, should cause suspicion and
investigation as to the character of the soil-drainage. Soil-moisture
is also an important factor in the development of periodical fevers,
and the effect of thorough drainage in diminishing malaria is now
generally understood.
It sometimes becomes an important question as to the influence which a
collection of water, such as a mill-pond or a reservoir, has upon the
health of a community, and the physician may be called on for an
opinion in such cases where large property interests are involved. The
essential points to be borne in mind are--first, that stagnant water
and damp soil do not in themselves produce malaria; there is something
else necessary, which is commonly designated by the word "germ."
Second, that they are in most cases essential conditions for the
production of the disease, so that if removed the disease will
disappear. Third, that the development of malaria may follow either
the rise or fall of the ground water. Fourth, that the condition of
the border of the collection of water as to presence of organic matter
and moisture is of more importance than the pool itself. And, finally,
that each case is a problem by itself, to be determined by the history
of the sickness of the vicinity, and that only probabilities can be
stated in any case, although these probabilities may be so great as to
amount, practically, to certainty. Of the four factors which appear to
be essential to the production of the malarial poison--viz. moisture,
high temperature, organic matter of vegetable origin, and certain
micro-organisms--the first is the one which in any given locality is
most under human control; it is the link in the chain of causation
which is most easily broken.
The influence of the rise and fall of the soil water in typhoid fever,
upon which so much stress is laid by Pettenkofer and others, no doubt
exists, acting in some cases through pollution of the drinking water
by the subsoil water leaking through a polluted soil; in other cases,
perhaps, by air from the soil bearing the unknown germ. The filtering
power of soil as regards air is, however, very great, a few inches of
sand being sufficient to remove the ordinary germs of putrefaction
from air drawn through it, and this for a long period; while, on the
{188} contrary, many feet of the same sand will not remove the germs
from water passed through it. Usually, as Dr. Parkes remarks, in an
examination of soil the immediate local conditions are of more
importance than the general geological formation, yet this last, as
influencing conformation and the movement of water and air over and
through a country, is also important. The practical questions on this
point are, what higher ground than the site in question exists in the
vicinity? what are the character and direction of the strata between
such elevation and the site? and, what sources of soil-pollution exist
on the higher level? As to the site itself, is it on made ground? what
is the height of the foundation above the subsoil water? and, what
precautions have been taken to secure drainage and to cut off
communication between the interior of the house and the ground air?
Probably a trial excavation or boring may be necessary to determine
some of these points.
The level of the subsoil water should be at least five feet below the
foundations, although it is often impossible to obtain this. At all
times when the temperature of the house is higher than that of the
external air--_i.e._ during a large part of the year and nearly every
night--there is a strong and constant aspirating force at work to draw
into the house, through the cellar floor and walls, all gases and
vapors contained in the adjoining soil. If this soil contains a large
proportion of organic matter, as is often the case in filled-in ground
in cities, or if there be a leaky cesspool or sewer or gas-pipe under
or near the house, the ground air passing into the house may be of
such a character as to be positively dangerous to its occupants. For
this reason it is very undesirable to have a sewer or soil-pipe
crossing beneath the site of a house, and when such location is a
necessity, as it often is in cities, the soil-pipe should be laid in a
cement-lined trench covered with a movable flap, so that it can always
be easily inspected and any leaks detected and remedied. Dampness in
the cellar or basement of a house is always a sign of danger. The
exhalation of gases and vapors from the ground into the house can be
to a great extent cut off by a layer of impervious material, such as
concrete covered with asphalt, but this layer must cover the sides of
the cellar as well as the floor to be thoroughly efficient. If a house
have no cellar, the space between the floor and the ground should be
thoroughly ventilated; and for this purpose, as well as to secure
cleanliness, the floor should be sufficiently elevated to permit of
easy access beneath it.
Next to its dryness, the nature and condition of the arrangements for
removing excreta and soiled water from a house are of the greatest
importance in determining its healthfulness; and in cities it is with
regard to the sufficiency of these, including the whole system of
house-plumbing and pipe-fitting, that the inquiries of one wishing to
determine as to the presence or absence of causes of disease will most
frequently be directed. The soil-pipes, etc. of a house are commonly
referred to as constituting the system of house-drainage, but it is
desirable to use another term, for we need the word "drainage" to
describe the removal of surface and subsoil water, and it should be
distinguished from "sewerage," which has a different purpose and
requirements.
In a properly-arranged system of house sewerage all the pipes, traps,
etc. are easily accessible for purposes of inspection, and an
examination of them is a comparatively simple matter. This examination
is to be {189} made with reference to the following points: 1. Are all
the pipes, joints, and connections air-tight? 2. Is the soil-pipe well
ventilated, or has it dead ends? 3. Is the communication between the
soil-pipe and the street sewer uninterrupted? 4. Are the pipes
properly trapped, and is there liability to the removal of water from
any of the traps, either by siphonage or evaporation, to such an
extent as to break the seal? 5. Is the water-supply of each closet
entirely cut off from the main supply to the house by means of a tank
or cistern?
In houses as heretofore constructed it is often very difficult to
obtain satisfactory information upon these points, because a large
part of the soil-pipe and its connections is buried beneath the house
or concealed in the walls or floors; in which case the services of a
skilled mechanic will usually be necessary to obtain access to the
various parts of the system. In a paper of this kind it is of course
impossible to go into details as to methods of inspection, or as to
what is and what is not satisfactory; but the following are the
general principles upon which a judgment as to the merits of a system
should be formed, and these should be so clearly understood by every
physician that he can be neither persuaded nor frightened into
thinking them incorrect by the eloquence of the man with a patent
remedy to dispose of. The principal dangers to health from house
sewerage are due, first, to the passage of air from the general system
of sewers or from a cesspool into the house through the soil-pipe and
its connections; second, to the generation of offensive and dangerous
gases and organisms in the soil-pipe itself, and the passage of these
into the house; third, to leakage of soil-pipe causing contamination
of the water-supply either by improper connections of water-pipes with
water-closets or slop-hoppers, or by contamination of wells, cisterns,
or tanks with sewage or sewer gases.
There is, of course, no such thing as a sewer gas having a definite
and distinctive composition, and the nature of the mixture of gases in
sewers is constantly varying according to season, temperature, etc.
The tendency which sewer air has to cause disease depends in part upon
certain gases, in part on minute particles of solid or semi-solid
matter which are suspended in the air. In rare instances the sewers
also contain illuminating gas, derived from leakage of gas-pipes in
the vicinity. These gases produce debility, headache, loss of
appetite, etc. As found in sewers and soil-pipes, they are so diluted
that they are not absorbed by the water of a trap and given off on the
other side to a sufficient extent to produce an evil effect. The air
in a soil-pipe which is not ventilated is much more impure than that
of the ordinary sewer, since the process of decomposition is
constantly going on in the slimy coat which lines the interior of the
pipes; and it is for this reason that it is so important to secure
thorough ventilation of all the soil-pipes in a building. When this
ventilation is secured, the proportion of dangerous gas in the pipes
becomes very small, and the amount absorbed by the water in traps is
almost inappreciable. The chief danger to life from sewer and
soil-pipe air arises from the presence of minute particles of organic
matter, dead and living, the so-called germs. Danger to life from
these germs cannot be entirely removed by dilution, as can be done
with gases. It has been found by the experiments of Dr. Carmichael and
Dr. Wernick that an ordinary water-trap entirely prevents the passage
of these germs, and that organic putrescible fluid will remain
unchanged when exposed only to the air immediately {190} above such a
trap. A pin-hole or minute sand-crack in the soil-pipe, or a very
slight defect in a joint, is far more dangerous than a trap.
The forms of disease produced by sewer air and its contents are more
especially diphtheria, typhoid fever, and ill-defined disorders of the
throat and digestive organs. It is possible that the germs of other
specific diseases, such as scarlet fever, may be at times transmitted
through sewer air, but such transmission must be very rare. While it
is true that the germs of the specific diseases are very rarely
present in sewer air, the house system of sewerage must be arranged as
if they were always present, in order to obtain security. It must also
be remembered that a system originally well planned and properly
constructed will not always remain so; the pipes will corrode, the
joints will become loosened, the valves will become clogged, and
whenever alterations or repairs are made there is always danger of
injury. Bearing these points in mind, the method of investigating a
system can be readily understood.
The first step is to ascertain whether there is a trap outside the
house disconnecting the sewer from the house system and permitting
inspection. If there is not, the first thing to be done is to make an
excavation and open the drain at the proper point for placing such a
trap. The next step is to set the water flowing in the various closets
and watch the flow at the external trap, or opening, which has been
made to ascertain whether there is any obstruction in the pipe within
the house. If the sewer is properly arranged for inspection, as has
been above suggested, to determine whether there is any leakage from
the sewer under the house will be an easy matter; if, however, it is
buried beneath the cellar floor, as is usually the case, an excavation
should be made along the floor in the line of the pipe, with a view to
having it properly arranged, as well as for the purpose of examining
the soil. It may also be tested by opening the upright soil-pipes at
the farther end of the house-drain at the height of three or four feet
above the floor and pouring water into it, having temporarily stopped
up the drain at the external trap or opening. If the water remain at a
constant level in the upright piece, the sewer is water-tight; if not,
the leakage may be ascertained by the rate at which it sinks. Having
settled this, the next point is to determine whether all the
soil-pipes are air-tight and properly trapped. The test usually
applied for this purpose is the pouring of a small quantity of strong
oil of peppermint, followed by a dash of hot water, into the top of
the soil-pipe, which should always pass through the roof and be freely
opened to the outer air. If the odor of the oil is perceptible in the
house, it indicates a leak, which must be further sought for. Ether
may be used for the same purpose. The smoke test is, however, the
best, but it requires a special apparatus which as yet is little used
in this country. It is applied by a small machine with a fan, by which
the smoke from burning cotton-waste saturated with oil, or of coarse
brown paper impregnated with sulphur, can be blown into the pipes;
this locates leaks with great precision.
It is not, of course, expected that a physician will personally make
the examination necessary to determine whether the plumbing of a house
is in good order, but he should be able to make it, if necessary, if
for no other purpose than to know whether the inspector employed for
the purpose understands his business.
The dangers to health from a properly-constructed system of house
{191} sewerage, such as is now generally agreed upon by sanitary
engineers, are so very small as to practically amount to nothing,
being, in fact, less than those of a well-kept yard privy of a country
house, setting aside altogether the question of water pollution. The
real difficulties in the way are the expense of such a system, which
is considerable, and the finding of skilled and honest workmen to
construct it and keep it in repair. Not every one who chooses to style
himself a sanitary engineer or a sanitary plumber is to be regarded as
such, by any means, but the physician should make it his business to
know who are really reliable in this respect, for he will constantly
be called in for advice on this point by those who have learned that
good plumbing is the only true economy, but who do not feel themselves
competent to distinguish between good and bad work. The main points of
a satisfactory system are the following.[3]
[Footnote 3: For further details consult the following: _American
Sanitary Engineering_, by E. S. Philbrick, N.Y., 1881; _House-Drainage
and Water-Service_, by James C. Bayles, N.Y., 1878; "House-Drainage
and Sanitary Plumbing," by W. P. Gerhard, in _Fourth Annual Report
State Board of Health Rhode Island_, 1882; _The Sanitary Engineer_, a
weekly journal published at 140 William St., New York City.]
1. All soil- and waste-pipes should be extended up to and through the
roof, and be freely open at the top. The extension of the soil-pipe
should be full size--_i.e._ from four to six inches in diameter.
2. There should be a fresh-air inlet in the house sewer just outside
the house, and between this inlet and the main sewer should be a trap
so arranged as to permit of inspection. This prevents the ventilation
of sewers through the soil-pipes. If a perfect system of sewers,
uniformity of house-connections, and uniform height of houses could be
guaranteed, this inlet and trap would not be so necessary, although
even then it would be useful.
3. Every water-closet, wash-bowl, bath-tub, sink, etc. should have a
trap placed as close to it as possible. This trap is desirable,
whether the discharge be into the sewer system or not. For example, a
kitchen sink, the pipe from which passes to the outer air and
discharges there, should be trapped, for this pipe is foul, and if it
be untrapped will act as an air-inlet.