been growing more and more impure, as the city has increased in size,
until a very large proportion of it, is entirely unfit for culinary
and dietetic purposes. That in the lower part of the city, has always
been, more or less, brackish, owing to the percolation of the salt
water from the north and east rivers through the loose sandy soil, thus
giving them a distinct saline impregnation. The amount of impurities
contained in these waters, varies, therefore, in different parts of the
city, according to its elevation, and the denseness of the population.
A gallon of water from the well belonging to the Manhattan Company
in Reade-street, yielded 125 grains of solid matter; while the same
quantity of water, from their well in Bleecker-street, yielded 20
grains, and in 13th street, 14 grains. A gallon of water taken from
four of the city wells in the densely populated parts of the city
yielded on an average, 58 grains each of solid matter.
The supply also of well water has been gradually diminishing in this
city for the last several years. For example, at the Chemical Works
on the North River, at 33d street, and at an extensive distillery on
the East River, some distance above the Alms House, water cannot be
procured in sufficient quantities on their premises, where, but a few
years past, it was obtained in great abundance. At the Gas Works on
the Collect grounds, where they have a well 20 feet in depth, by 18
feet in diameter, which, until 1834, furnished water freely, enabling
the engine to raise 20,000 gallons in ten hours, in 1835 it required
14 to 16 hours to raise the same quantity, and in order to continue
the supply, it was found necessary to return the water to the well,
after using it for condensing the gas. The Corporation well, also,
in 13th street, furnished, for several years, about 120,000 gallons
of water daily, but in 1835, this quantity was reduced down to from
five to ten thousand. In order to remedy this evil, a well was sunk at
Jefferson Market, which in a short time deprived most of the wells in
that vicinity, of water; thus drying up one source of supply, in order
to increase that of another. There is, therefore, every probability
that had not water been introduced into the city of New-York from
abroad, the supply from the wells would, in a few years, have been
insufficient for the economical, domestic and manufacturing purposes of
the inhabitants. It is fearful to contemplate the amount of decomposing
organic matter contained in the wells in the vicinity of Trinity, St.
Paul’s, and St. John’s burying grounds, which for more than a century
furnished the only water used by those residing in their neighborhood.
No one can doubt that the use of such water, as well as that from the
wells on the Collect, and over the greater portion of the city below
Canal-street, must have proved extremely detrimental to the health of
the citizens, and especially to children, and infants. We believe,
therefore that the introduction of the Croton water, will increase the
average duration of human life in the city of New-York, from 8 to 12
per cent. From 1815 to 1836, it ranged from 30.08 to 22.05, (in 1836),
but the mean duration of life for the last 20 years is about 25 years;
and the ratio of mortality, according to population, about as 1 to 35.
From the manner, however, in which the inspector’s reports have been
made, from the imperfection of the law, no great confidence can be
placed in the returns,--those carried out of the city for burial, not
having been included.
From a “Report on the subject of introducing pure and wholesome water
into the city of Boston, by L. Baldwin, Esq., Civil Engineer,” it
appears that the whole number of wells in that city in 1835, was 2,767.
The water from 2,085 of these wells was drinkable, though brackish
and hard, and 682 of them were bad and unfit for use. There were only
seven of the city wells which yielded soft water occasionally and for
washing, and from 33 of them the water was obtained by deep boring.
“Within a few years,” says the Report, “it has become common in Boston,
and the vicinity, to bore for water, and to make what are called
Artesian wells. But no certain or valuable result has grown out of
these endeavors. There are 33 bored wells, only two of which are stated
as furnishing soft water. The same remarks will apply to the public
wells of this city, the most of which produce nothing but hard and
brackish water, and none of which is sufficiently soft to authorize its
use in washing clothes,” &c.
LAKE WATER is a collection of rain, spring and river water, usually
more or less contaminated with putrefying organic matter. It is
generally _soft_, and when filtered, is as good and wholesome as any
other description of waters. Though lake water cannot be characterized
as having any invariable qualities; yet most of the Lakes of the United
States, especially our great ones, afford a very pure water. In many
of our smaller lakes the water is more or less stagnant, and of course
very unhealthy.
_Marsh Water._ This is analogous to lake water, except that it is
altogether stagnant and is more loaded with putrescent matter.
The sulphates in sea and other waters are decomposed by putrefying
vegetable matter, with the evolution of sulphuretted hydrogen; hence
the intolerable stench from marshy and swampy grounds liable to
occasional inundations from the sea. Marsh water cannot be drunk with
safety either by man or beast.
_Tests of the usual impurities in Common Water._
The following are the tests by which the presence of the ordinary
constituents or impurities of common waters may be ascertained.
1. EBULLITION.--By boiling, air and carbonic acid gas are expelled,
while carbonate of lime, (which has been held in solution by the
carbonic acid) is deposited. The latter constitutes the crust which
lines tea-kettles and boilers.
2. PROTOSULPHATE OF IRON. If a crystal of this salt be introduced into
a phial filled with the water to be examined, and the phial be well
corked, a yellowish-brown precipitate (sesquioxide of iron) will be
deposited in a few days, if oxygen gas be contained in the water.
3. LITMUS. Infusion of litmus or syrup of violets is reddened by a free
acid.
4. LIME WATER. This is a test for carbonic acid, with which it causes a
white precipitate (carbonate of lime) if employed before the water is
boiled.
5. CHLORIDE OF BARIUM. A solution of this salt usually yields, with
well water, a white precipitate insoluble in nitric acid. This
indicates the presence of sulphuric acid (which, in common water, is
combined with lime).
6. OXALATE OF AMMONIA. If this salt yield a white precipitate, it
indicates the presence of lime, (carbonate and sulphate.)
7. NITRATE OF SILVER. If this occasion a precipitate insoluble in
nitric acid, the presence of chlorine may be inferred.
8. PHOSPHATE OF SODA. If the lime contained in common water be removed
by ebullition and oxalic acid, and to the strained and transparent
water, ammonia and phosphate of soda be added, any magnesia present
will, in the course of a few hours, be precipitated in the form of the
white ammoniacal phosphate of magnesia.
9. TINCTURE OF GALLS. This is used as a test for Iron, with solutions
of which it forms an inky liquor, (tannate and gallate of iron).
If the test produce this effect on the water before, but not after
boiling, the iron is in the state of carbonate; if after, as well
as before, in that of sulphate. Tea may be substituted for galls,
to which its effects and indications are similar. _Ferro cyanide of
potassium_ yields, with solutions of the sesqui-salts of iron, a blue
precipitate, and with the proto-salts a white precipitate, which
becomes blue by exposure to the air.
10. HYDROSULPHURIC ACID. (_Sulphuretted Hydrogen._) This yields a
dark (brown or black) precipitate, (a metallic sulphuret) with water
containing iron or lead in solution.
11. EVAPORATION AND IGNITION. If the water be evaporated to dryness,
and ignited in a glass tube, the presence of organic matter may be
inferred by the odor and smoke evolved, as well as by the charring.
Another mode of detecting organic matter is by adding nitrate (or
acetate) of lead to the inspected water, and collecting and igniting
the precipitate; when globules of metallic lead are obtained if organic
matter be present. The putrefaction of water is another proof of the
presence of this matter. Nitrate of silver is the best test for the
presence of chloride of soda or common salt. By adding a small quantity
of this to the common well water of New-York, a copious, white,
flocculent precipitate is immediately formed, which is the chloride of
soda. The same test, however, applied to the Croton water, produces no
discoloration whatever.
_Purification of Common water._ By _filtration_, water may be deprived
of living beings and of all suspended impurities; but substances
held in solution, cannot thus be separated. _Ebullition_ destroys
the vitality of both animals and vegetables; expels air, or carbonic
acid, and causes the precipitation of carbonate of lime, but the
water should be afterwards subjected to the process of _filtration_.
_Distillation_, when properly conducted is the most effectual method
of purifying water. But distilled water is in general contaminated by
traces of organic matter. The addition of chemical agents is another
mode which has been proposed and practised, for freeing water from
some of its impurities. _Alum_ is often used by the common people to
cleanse muddy water, and ashes and pearl-ash to destroy its hardness.
When alum is used, two or three grains are sufficient for a quart of
water. The alum decomposes the carbonate of lime; sulphate of lime is
formed in solution, and the alumina precipitates in flocks, carrying
with it mechanical impurities. This agent, however, adds nothing to
the chemical purity of the water, but by converting the carbonate into
sulphate of lime augments its hardness. _Caustic alkalies_ added to
lime saturate the excess of carbonic acid, and throw down the carbonate
of lime, having an alkaline carbonate in solution. Professor Clark
of Aberdeen,[12] (Scotland) has recently patented a plan for the
purification of water, by the addition of lime. The lime unites with
the excess of carbonic acid in the water, and forms carbonate of lime
(chalk) which precipitates, along with the carbonate of lime held
previously in solution in the water. The effect of this process is
similar to that of ebullition,--as the hardness of water is, however,
owing to the sulphate and not the carbonate of lime,[13] this plan can
have little or no influence in rendering hard water soft. Alkaline
carbonates soften water, decompose all the earthy salts (calcareous and
magnesian carbonates, sulphates, and chlorides) and precipitate the
earthy matters. They leave, however, in solution, an alkaline salt, but
which does not communicate to water the property of hardness.
SEA-WATER includes the waters of the ocean and of those lakes, called
island seas, which possess a similar composition. The Dead Sea,
however, varies so much from ordinary sea-water, as to rank amongst
mineral waters.
The quantity of solid matter varies considerably in the waters of
different seas, as the following statement proves--
_10,000 parts of water of_ _Solid constituents._
_the Mediterranean Sea_, contain 410 grs.
English Channel, 380 „
{ At the Island of Fohe, 345 „
German Ocean { At the Island of Norderney, 342 „
{ In the Frith of Forth, 312 „
{ At Ritzebuttle, 312 „
At Apemalle, in Sleswick, 216 „
At Kiel, in Holstein, 200 „
Baltic Sea At Doberan, in Mecklenbergh, 168 „
At Travemunæ, 167 „
At Zoppot, in Mecklenbergh, 76 „
At Carshamm, 66 „
The average quantity of saline matter in sea-water is 3½ per cent.,
and its specific gravity about 1.0274. The composition of sea-water
differs also in different localities. Iodine has been found in the
Mediterranean sea.
_Action of Water on Lead._ When lead is exposed to atmospheric air,
the oxygen of the air combining with it, forms an oxide, while, at
the same time the carbonic acid of the air, unites with it forming a
thin white crust, which is the _carbonate of lead_. This formation is
accelerated by moisture, and by the presence of an unusual quantity of
carbonic acid in the atmosphere. The same process goes on with still
greater rapidity in pure running water. But if water be deprived of
all its gases by ebullition, and excluded from contact with the air,
the lead will not be acted upon If water, however, be exposed to the
air, although all the gases have been expelled, a white powder will
soon form around the lead, till, in the course of a few days, there is
formed a large quantity of white, pearly scales, which partly float
in the water, but are chiefly deposited on the bottom of the vessel.
In 12 ounces of distilled water, contained in a shallow glass basin,
loosely covered to exclude the dust, twelve brightly polished lead
rods weighing 340 grains, will lose 2½ grains in 8 days, and the lead
will show evident marks of corrosion; and this action will go on as
long as the water is exposed to the air. While these changes are going
on, a small quantity of lead will be dissolved, as may be shown by
carefully filtering the water acidulating with a drop or two of nitric
acid, and evaporating to dryness. Sulphuretted hydrogen is also a good
test, occasioning, where lead is present, first a brown color, and
subsequently a black precipitate. Christison has proved that the lead
which is dissolved, is in the form of the carbonate, and hydrate of the
oxide, or, oxide of lead, carbonic acid and water.
The fact is then sufficiently established, that distilled water has
the property of dissolving lead--Does the same hold true in relation
to waters in ordinary use? In the year 1809, it was first announced by
_Guyton Morveau_, that the salts which are held in solution by some
natural waters, destroy their property of acting on lead, and that of
these modifying circumstances none are more remarkable in their action
than the neutral salts. Dr. Christison has pursued this investigation
with great success, and has proved that this preservative power
exists in the case of sulphates, muriates, carbonates, hydriodates,
phosphates, nitrates, acetates, tartrates, arseniates, &c. These
salts, however, do not possess an equally protective influence, the
carbonates and sulphates being most, the chlorides the least energetic
of those saline substances commonly met with in waters. As a general
rule, it appears that those whose acid forms with the lead a soluble
salt of lead, are the least energetic; while those whose acid forms an
insoluble salt of lead, are most energetic. The variable quantity of
salts necessary to prevent the action of water on lead, may be seen
from the following results obtained by actual experiment.
Of acetate of soda a 100th part of the water is a preservative.
Of arseniate of soda 12,000th „ „ „
Of phosphate of soda 30,000th „ „ „
Of hydriodate of potash 30,000th „ „ „
Of muriate of soda 2,000th „ „ „
Of sulphate of lime 4,000th „ „ „
Of nitrate of potash 100th „ „ „
The sulphates of soda, magnesia, lime, and the triple sulphate of
alumina and potash, possess about the same preservative power; which
appears to depend on the acid, not on the base of the salt. The general
results of Dr. Christison’s investigations, appear to be, that neutral
salts in various, and for the most part minute, proportions, retard or
prevent the corrosive action of water on lead--allowing the carbonate
to deposit itself slowly, and to adhere with such firmness to the
lead as not to be afterwards removed by moderate agitation,--adding
subsequently to this crust other insoluble salts of lead, the acids
of which are derived from the neutral salts in solution,--and thus at
length forming a permanent and impermeable screen in the form of a
film over its surface, through which the action of the water cannot
any longer be carried on. These films are composed of the carbonate of
lead, with a little of the muriate, sulphate, arseniate, or phosphate
of lead, according to the nature of the acid in the alkaline salt,
which is dissolved in the water. The following general conclusions may
therefore be considered as sufficiently established.
1. Lead pipes ought not to be used for the purpose of conducting
water, at least where the distance is considerable, without a careful
examination of the water to be transmitted.
2. The risk of a dangerous impregnation with lead is greatest in the
instance of the purest waters.
3. Water, which tarnishes polished lead when left at rest upon it in
a glass vessel for a few hours, cannot safely be transmitted through
lead-pipes without certain precautions; and conversely, it is probable,
that if lead remain untarnished, or nearly so, for 24 hours in a glass
of water, the water may be safely conducted through lead-pipes.
4. Water which contains less than about an 8000th of salts in solution,
can not be safely conducted in lead pipes without certain precautions.
5. Even this proportion will prove insufficient to prevent corrosion,
unless a considerable part of the saline matter consists of carbonates
and sulphates, especially the former.
6. So large a proportion as a 4000th part, probably even a considerably
larger proportion, will be insufficient, if the salts in solution be in
a great measure muriates.
7. In all cases careful examination should be made of the water
after it has been running a few days through the pipes; for it is
not improbable that other circumstances, besides those hitherto
ascertained, may regulate the preventive influence of the neutral salts.
8. Where the water is of sufficient purity to act on lead, a remedy
may be found, either, in leaving the pipes full of water and at rest
for three or four months, or by solution of phosphate of soda; in the
proportion of about a 25,600th part.[14]
Dr. Kane, however, seems to differ from Dr. Christison in opinion on
this subject; for after having mentioned the crust which gradually
forms on the interior of the cistern, and assists in protecting it from
the oxidizing action of the air, he remarks, “no danger is therefore
to be apprehended from the supply of water to a city being conveyed
through leaden pipes, and preserved in leaden cisterns; for _all water
of mineral origin dissolves, in filtering through the layers of rocks
in its passage to the surface_, a sufficiency of saline matters to
serve for its protection.”
Now, to apply these results to the water of the Croton; as this holds
in solution only about one 18,000th part of salts, it must, according
to Christison, exert a corroding influence on the lead-pipes. Dr.
Dana, of Lowell, has lately investigated this subject and detected
lead in the water which had passed through the leaden-pipes for the
distribution of water in the city of Lowell. The first examination was
made from a sample of water taken from the source or spring-head before
it had entered the leaden pipes, when the specific gravity was found to
be 1,000,18. The pint, on evaporation to dryness, yielded 2.37 grains
of solid matter. The solid contents of an imperial pint were found to
be,
_Grains._
Chloride of Sodium, 1.54
Chloride of Magnesia, 0.71
Sulphate of Lime, 0.128
------
A trace of Carbonic acid,
Grains, 2.378
Excess in the course of analysis .008
The second examination was made of water taken from the leaden pipes
when the specific gravity was found to be 1.000.42. Upon a pint of
this water being evaporated to dryness it yielded two grains of solid
matter, (viz.)
Carbonate of lead 164 Grains,
Organic matter and salts 038 „
---
202 „
Excess in analysis, 002 „
It therefore has been calculated that every gallon of the water used
after passing through the leaden pipes, contains 1.312 grains of the
carbonate of lead. Such water, although it would not speedily destroy
life, would undoubtedly be attended with injurious consequences, should
its use be habitually continued.
On the other hand, Dr. Hare of Philadelphia, in reply to a letter
requesting his opinion as to the action of the Schuylkill water[15] on
lead pipes, states that after using the Schuylkill water for 25 years
in his laboratory, he has never perceived the slightest indication of
the presence of lead; and that if there had been any in the water, the
re-agents which he has been accustomed to use must have rendered the
impurity evident. If it be true that the Schuylkill water does not act
upon the lead pipes, it would follow as a matter of course, if the
doctrines above laid down be correct, that the Croton, which contains
very nearly the same quantity of saline ingredients, would also exert
no influence upon this metal. In cases, however, where injurious
consequences have resulted from the agency of lead, the pipes through
which the water was conducted, were of considerable length; suppose for
example that the pipes are 4000 feet long, and three fourths of an inch
in diameter, each portion of water will pass successively over no less
than 784 square feet of lead before being discharged; and it would not
therefore be at all remarkable, if the water were found contaminated
with the lead. In this city, however, the pipes are rarely more than 50
feet in length, generally not more than 25, and therefore cannot exert
so deleterious an influence as in those of greater extent. Dr. Chilton,
recently inspected the Croton water drawn from the leaden pipes, by
which it is introduced into the house of Mr. G. D. Coggeshall. No 421
Pearl-street in this city, and found the water evidently affected
by the lead. He has also obtained similar results in several other
instances. If the precaution be used, of not employing the water first
drawn from the pipes for dietetic and culinary purposes, no injurious
consequences would probably attend the use of water conveyed in this
metal, but as this is not likely to be attended to generally, it is
expedient to employ other measures to guard against its deleterious
effects.
For this purpose, various means have been suggested, such as the
substitution of block-tin and other metals not acted upon by water;
but the most efficient, scientific, and useful, as well as the most
economical, of all the plans hitherto proposed, is that introduced by
Thomas Ewbank, Esq., of coating the lead-pipes with tin both inside and
out. The process, which has been patented, consists simply in drawing
an ordinary lead-pipe through a bath of melted tin, coated with a layer
of melted rosin, which leaves a continuous deposit, of tin upon both
sides of the pipe, of sufficient thickness, to effectually prevent
any oxidation of the lead. These pipes have been highly recommended
by our first chemists, and other men of science, as furnishing an
effectual safeguard against the corroding effects of pure water This
highly ingenious process, strengthens the pipe, without diminishing
its elasticity, and although some small portions of the lead should
escape being coated, yet the proximity of the tin, will, from galvanic
action, probably prevent oxidization of the lead. As these pipes are
furnished at about eight cents per pound, the usual price of ordinary
lead-pipe, there can be no doubt that they will be generally adopted by
our citizens,--as they have been, already, by the Corporation, in the
conveyance of the Croton water, into the public buildings.
_Use of Water as Aliment._ Water is the beverage provided by nature for
all animated beings. It is a vital stimulus, or one of the external
conditions essential for the manifestations of life. Consequently,
without it, life, at least in the higher order of animals, could not be
maintained.
Considered in a dietetical point of view, water serves three important
purposes in the animal economy; namely, it repairs the loss of the
aqueous part of the blood, caused by the action of the secreting and
exhaling organs; secondly, it is a solvent of various alimentary
substances, and therefore assists the stomach in the act of digestion,
though, if taken in very large quantities, it may have an opposite
effect, by diluting the gastric juice; thirdly, it is a nutritive
agent, that is, it assists in the formation of the solid parts of the
body.