A STUDY 
OF 
WATER IN RELATION TO HEALTH AND DISEASE. 
GEO. M. KOBER, M.D., of Fort Bidwell, Cal. 
[Reprint from Thirteenth Annual Report of the State Board of Health, 1894.] 
STATE OFFICE, : : : A. J. JOHNSTON, SUPT. STATE PRINTING. 
SACRAMENTO: 
1894. A STUDY OF WATER IN RELATION TO HEALTH AND 
DISEASE. 
By George M. Kober, M.D., of Fort Bidwell, Modoc County, California. 
It is impossible to overestimate the importance of water from a sani- 
tary point of view, for it is not only essential as an article of food, but 
also for the proper degree of cleanliness of our persons, clothing, dwell- 
ings, and surroundings. This fact appears to have been duly appreciated 
by the settlers in all regions, since homes sprang first into existence 
wherever nature yielded a bountiful supply of water; indeed, even now we 
see this well illustrated in the settlement of our own continent. Look 
where we may, and the land supplied with a spring or traversed by a 
stream constituted the first choice of our sturdy pioneers. In our towns 
and cities, the question of water supply has been solved by the intro- 
duction of waterworks, but even these vast enterprises are not of modern 
origin, for in a visit to Rome we will be shown aqueducts which were 
begun 312 B. C.; these were so large and numerous, that they supplied 
certainly not less than 300 gallons per head daily for a population of 
about a million people. Many of these ancient aqueducts have been 
thoroughly repaired and furnish to modern Rome about 3,000 liters per 
head. The old Romans were very fond of public and private baths and 
fountains, as evinced by the baths of Caracalla, the largest mass of 
ruins in Rome, except the Coliseum; they cover an area of 2,625,000 
square yards, and could accommodate one thousand six hundred bathers 
at one time. 
Sources of Water.-The water which we require for our daily use comes 
to us from the clouds in the form of rain or snow. Of this a certain 
amount is evaporated; another portion may be collected in cisterns; 
another soaks into the earth, to reappear in the form of springs; another 
portion flows off in the direction of surface decline, to join the ponds, 
streams, or rivers, or it may penetrate the earth sufficiently deep to 
require us to dig wells for its collection. A high temperature naturally 
favors rapid evaporation. Some of the water which has percolated into 
the soil is for the time being absorbed by the roots of vegetation; but in 
reality there is no loss in nature. 
The sources of our water supply may therefore be classified as rain 
water, surface water (including springs, ponds, streams, rivers), and well 
water. 
1. Rain Water. 
The mean annual rainfall for different portions of the United States 
has been tabulated by Dr. Waller, and may be briefly stated as follows: 
Inches. 
Northern States east of the Rocky Mountains 
30 to 50 
Southern States 
50 to 70 
Between the Rocky Mountains and the Pacific Coast Range 
10 to 20 
San Francisco 
20 to 25 4 
Along the North Pacific coast the rainfall increases, amounting to 
between 70 and 80 inches at Vancouver Island. As we recede from the 
coast in any country the rainfall diminishes. Fanning gives the average 
of 40 inches for New England and the Middle States. 
One inch of rain would amount, according to Church, to nearly 101 
(gross) tons per acre, or on a house-roof of say 20x20 feet area, one inch 
of rain would be about 250 gallons. With a rainfall of 40 inches per 
annum, this would amount to 10,000 gallons, or 27 gallons per day. 
The average daily supply per head in most of our northern cities 
ranges from 20 to 127 gallons, or more, per day. (Fanning.) 
Sources of Impurities in Rain Water.-Rain in its passage to the 
earth absorbs various impurities from the atmosphere, and these may 
be augmented from the surface upon which it is received and the recep- 
tacles in which it is collected. The impurities in the air are gaseous; 
the rain water becomes highly aerated, absorbs ammoniac salts, nitric 
and nitrous acids in small amounts, and, near the sea, chloride of 
sodium. Air contains on an average about 0.5 gramme of solid matter 
per 1,000 cubic meters (Remsen), which is equivalent to a little over 0.2 
grain per 1,000 cubic feet. The observations of Dr. Miguel at Mont- 
souris show that the rain washes out of the air immense numbers of 
bacteria, fungoid organisms, and their spores; their number is always 
greater in warm weather and in the first shower, or after a prolonged 
dry season, when as many as 200,000 germs per liter have been found. 
Parkes tells us that the majority of these organisms are micrococci, and 
that they, as well as the bacilli and bacteria found in rain, exist to a 
larger extent in the form of germs or spores than in the adult state. 
In addition, pollen of grasses, flowers, microscopic plants (Protococcus 
pluvialisf and spores of fungi are found in rain, the latter often in suf- 
ficient quantity to cause the so-called " colored rain." 
During the prevalence of infectious diseases, there is a possibility that 
the respective germs may thus contaminate the drinking water. The 
amount of organic matter varies greatly in different localities, and it is 
to be hoped that examinations in that direction will be more frequently 
made in this country. The following table shows the average composi- 
tion of seventy-three different samples of rain water collected twenty- 
five miles from London, on a specially prepared surface: 
Parts per 100,000. 
Organic carbon 
0.099 
Organic nitrogen 
0.022 
Ammonia 
0.050 
Nitrogen as nitrates and nitrites 
0.007 
Chlorine 
0.63 
Hardness 
0.62 
Total solids on evaporation 
3.95 
The rain falling in towns contains also more or less sulphurous acid, 
from combustion of coal, and numerous sooty particles. 
It has been truthfully said that rain is a great " purifier of the air," 
but this also implies that rain water is far from being chemically pure; 
i. e., a compound of oxygen and hydrogen. 
Surfaces for Collection.-The roofs of houses are most commonly used 
as collecting surfaces for rain water. When we remember the accumu- 
lations of dust, soot, vegetable and animal matter (leaves and excre- 5 
ment of birds), the lodgment of minute plants, spores, and germs, per- 
haps deposits of slops carelessly thrown from the upper windows, we see 
at once the necessity for rejecting the first portions of the rainfall; for 
this purpose " cut-offs" have been invented, some of them automatic, by 
which the first portions of the rain are run to waste, and only the purer 
after-fall is turned into the storage cistern. The public should be made 
familiar with these facts. At present, Dr. Smart tells us that these 
separators are but little used. In this connection, it is well to refer to 
the material of the roof surface, if the water is to be collected for domestic 
purposes. Painted or galvanized roofs are liable to contaminate the 
water with particles of paint or zinc; shingled roofs impart portions of 
decaying wood, and are, moreover, like tiled roofs, peculiarly prone to 
collect dust and develop the various fungoid growths. For all these 
reasons slate roofs should be preferred. 
Cisterns.-This brings us naturally to the consideration of the storage 
receptacles for rain water, commonly called cisterns, and the material 
of which they are constructed is an important factor as regards the 
purity of the water supply. 
Cisterns or tanks of wood are objectionable, as wood, especially when 
exposed to fluctuations of the water-line, rapidly decays and forms a 
breeding-place for minute worms and other animal organisms. Lead 
linings are more readily attacked by rain water than any other, and 
should not be used. This is due to the highly aerated character of rain 
water, and the presence of nitrates and chlorides; but the solution of 
lead may be prevented by the presence of sulphates, phosphates, and 
lime salts (Saunders). It is stated by Parkes that new lead-lined 
cisterns become rapidly coated with a carbonate or sulphate of lead 
when the water is hard, or with a carbonate and oxide when it is soft; 
that these deposits form a lining, which protects the surface of the metal 
from further action, and should therefore not be scraped when the cistern 
is being cleaned out. Cement linings contain more or less lime, and 
render the water hard; but the greatest objection is their liability to 
crack, allowing leakage from the cistern or the seepage of sewage matter 
into the cistern. Iron cisterns rust and discolor the water. Zinc is 
readily attacked and dissolved by water, and produces poisonous effects. 
Galvanized iron has been extensively used, and whilst comparatively 
safe, it has been known to impart zinc to the water. Slate is perhaps 
the best material for lining, but the cemented joints should not be 
repaired with red lead when they leak, as the lead oxides are decidedly 
objectionable. Stoneware cisterns, whilst very heavy and cumbersome, 
are valuable, since they give up nothing to water. These, or cisterns 
made of slate or galvanized iron, should be preferred. 
Location of Cisterns.-If located above ground for domestic uses, they 
should be placed in a light, well-ventilated, and cool position, to retard 
decomposition of organic matter, and properly covered. 
"The cistern should not be used directly to flush water-closets, but 
may supply the intercepting or waste-preventing cisterns, which should 
be used for this purpose. The overflow pipe must be carried out into 
the open air to terminate as a warning pipe; it may end over the open 
head of a rain-water pipe, if the cistern is in an upper story, or over a 
trapped siphon gulley when the cistern is near the ground." (Parkes.) 6 
In the construction of cisterns below the surface, the utmost care must 
be taken to prevent or arrest contamination of the water from slops, 
sewage, etc. The English River Pollution Commission found *a sample 
of cistern water "to consist of sewage of even greater strength than 
average London sewage." 
In addition to the danger just referred to, cistern water may be pol- 
luted by other impurities, such as dead rats, mice, birds, cockroaches, 
and other small vermin which have gained accidental access, and for 
all these reasons the cistern should be cleaned at regular intervals. 
Dr. Smart, of the United States Army, in his report to the National 
Board of Health, found the cisterns in New Orleans usually constructed 
of cypress wood, of an average capacity of about 2,000 gallons, and fre- 
quently located " in unventilated inclosures, rank with the emanations 
of unclean privies." 
The average accumulation of sediment, organic and inorganic, in cis- 
terns, is about one inch per annum. An analysis of the air-dried mud 
from one of these cisterns showed: 
Per Cent. 
Moisture 
17.2 
Organic and volatile 
34.0 
Mineral matter 
48.8 
The results of numerous investigations have led to the conclusion that 
cistern or rain water is never as free from organic contamination as the 
water from springs and wells, and therefore its use, except for laundry 
purposes, has been condemned. With the necessary care observed in 
the collection and storage, it would seem that rain water should prove 
useful for cooking and washing, on account of its softness, which is due 
to the absence of the salts of lime or magnesia-one grain of chalk wastes 
about eight grains of soap. The hardness of rain water is generally less 
than one half degree; that is to say, there is less than one half grain of 
chalk, or its equivalent salts, to the gallon of water, and is therefore 
especially valuable in localities where the other water supply is hard. 
In this connection it is proper to mention that some large cities, like 
Constantinople, Venice, Malta, and some of our Southern towns, are still 
either wholly or in part supplied with rain cistern water. 
Dr. Smart considers properly constructed underground cisterns prefer- 
able, because the cooler situation does not favor the fermentation of the 
accumulated sediment; moreover, the mineral or earthy matters of which 
the underground cistern is constructed introduce into the stored water 
certain bacteria, which transmute ammonia into nitric acid; they are 
the bacteria of nitrification. The organic matter of the water is first 
decomposed into ammonia, and this is subsequently transformed into 
nitric acid. The tendency of cistern water is to improve during its 
storage, but this does not hold good in wooden tanks, unless the bacteria 
of nitrification are introduced, as by throwing into the cistern a quan- 
tity of clean gravel, to which these bacteria adhere. 
The following table, taken from Dr. Waller's article (Parkes' Hygiene, 
vol. II, p. 406), shows how impure a cistern water may become: 7 
Analyses of Cistern Water. 
(Results expressed in parts per 100,000.) 
Location. 
Total Solids... 
Ammonia .... 
Albuminoid 
Ammonia... 
Hardness 
Chlorine 
Analyst. 
Podehole 
5.28 
0.130 
3.8 
0.9 
River Poll. Comm. 
Sheffield Barracks... 
12.00 
5.8 
1.6 
River Poll. Comm. 
Greasely 
126.60 
0.730 
0.008 
55.70 
11.5 
River Poll. Comm. 
Boston, Mass 
5.28 
0.013 
0.32 
W. R. Nichols. 
Newport, R. I 
7.50 
0.0105 
0.0275 
3.73 
0.76 
E. Waller. 
Omaha, Neb. 
6.70 
0.012 
0.0136 
4.03 
trace. 
E. Waller. 
Cincinnati, 0. .... 
2.68 
0.004 
0.123 
0.55 
C. H. Stuntz. 
Cincinnati, 0. 
4.48 
0.027 
0.118 
1.97 
C.H. Stuntz. 
Wilmington, N. C.... 
5.05 
0.002 
0.015 
0.70 
C. W. Dabney. 
Wilmington, N. C.... 
6.90 
0.016 
0.008 
- 
0.52 
C. W. Dabney. 
Snow Water is considered quite as impure as rain water, and possi- 
bly more so. Tissandier, quoted by Dr. Waller, obtained the following 
results with snow water after it had been melted: 
Falling in a court in Paris 
Solids per 100,000 parts. 
21.2 
Falling on towers of Notre Dame 
11.8 
Falling in the open country 
10.4 
About 60 per cent of these solids was mineral matter, and besides 
these the snow also contained ammonium nitrate. The amount of am- 
monia, and hence the probable amount of organic matter, has been 
found to vary with the temperature at which it falls, the nature of the 
surface on which it falls, and the character of the flakes. (See Vogel, p. 
407; Parkes, 2d vol.) In this connection the article of Dr. Charles 
Smart, U. S. A. (Am. Jour. Med. Sciences, Jan., 1878) is especially inter- 
esting. He found the greatest amount of ammonia in the first snows 
which fell in large heavy flakes at Camp Douglas, Utah, and attributes 
the origin of mountain fever to the malarious poison contained in such 
water. Dr. Brewer, of the Army, also speaks of the Western mountain- 
eers attributing this fever to the use of snow water. (Bucks' Hyg., II, 
pp. 129-134.) 
2. Surface Water. (Springs.) 
It has already been stated that a considerable portion of the rain soaks 
into the soil, and after percolating through a mass of rock and soil, 
undergoing nature's filtering process, it issues forth in the form of springs. 
In its passage through the soil it absorbs at once carbonic acid from the 
ground air, which contains two hundred and fifty times more of this gas 
than the normal atmosphere, and the absorption of this gas adds greatly 
to the dissolving power of water; hence, the mineral constituents 
derived from the rocks over which it passes. The quality of the water 
depends, therefore, largely upon the geological formation through which 
it passes. In general terms, the older non-calcareous rocks-granite, 
sandstone-afford the least amount of mineral matters, while the cal- 
careous formations yield the greatest amount. In some springs of great 
depth, the amount of mineral matter is so large as to render the water 
unfit for dietetic purposes; some of these min'eral springs are also thermal, 8 
indicating that they proceed from a great depth and are probably 
forced up by the pressure of confined expanding gases. But the springs 
which interest us most just now are formed in a different manner. The 
rain which sinks through the porous strata-gravel, chalk, sandstone, 
etc.-by reason of its gravity, may be arrested at a variable depth by 
an impermeable stratum of hard rock or clay. Here the water accumu- 
lates and forms those underground reservoirs of subsoil water which 
supply the springs and wells. The water naturally tends to find its 
own level, and may find this outlet into the sea, or a river, or in springs 
on a hill side at a much lower level. The springs are therefore formed 
by the " cropping out," on the surface of the earth, of such an imperme- 
able stratum, which prevents it from further percolation. 
Springs are spoken of as " main " and " land " springs. The former 
are the deep-seated springs issuing from regular geological formations 
(such as chalk, oolite, sandstone), and generally yield a constant flow, 
though subject to seasonal variations. The "land" springs draw their 
supply from a near and limited collection of underground water in 
superficial beds of sand and gravel overlying a stratum of clay; they 
are often intermittent, and frequently go " dry " during the summer 
months; they are also more liable to contamination than the main 
springs. 
The amount of water yielded by the springs is naturally influenced 
by the rainfall of the district, and the amount of evaporation; the latter 
explains the fact that during the winter months from October to March, 
springs yield a larger supply. The yield of a spring may be readily 
estimated by ascertaining the length of time required to fill a vessel of 
measured capacity. 
In the discovery of a new spring, it is advisable to determine as far as 
possible its source, as the following somewhat amusing incident, which 
occurred here, will indicate: A member of the Hospital Corps surprised 
the Post Surgeon with the announcement that he had discovered a spring 
near the brow of the hospital hill. The doctor found a clear, cold spring, 
yielding a large volume of water. The discovery was announced to the 
commanding officer, who repaired with his staff to the designated spot, 
and all regarded the clear, cool spring, in the midst of a California 
summer, with intense satisfaction. The water was pronounced superior 
to the water supply of the Post, which was a mountain stream distribu- 
ted in pipes from an impounding reservoir above the hospital. The 
commanding officer directed the Quartermaster to take the necessary 
steps for the protection and utilization of the spring. In the midst of 
this joy I was informed of the valuable discovery, but having served at 
the Post for several years, I was incredulous as to its being a natural 
spring, and suggested the possibility of a " leaky main." The suggestion 
was followed up, and led to the discovery of damaged water-closet pipes, 
a constant flow of water having passed through the closets, and a portion 
of the drain, by some unaccountable disunion in the latter, found its 
way into the soil, and being held up by an impermeable stratum, issued 
forth as a spring about one hundred yards below the hospital. It is 
needless to say that the spring disappeared after the repair of the pipes. 9 
Composition of Spring Water from different Formations. (Results given in parts per 100,000.) 
English River Pollution Commission, Sixth Report; quoted by Waller. 
Formation. 
Total Solids 
Organic Carbon 
Organic Nitrogen 
Ammonia 
Nitrogen as Nitrates, etc. 
Chlorine 
Hardness 
3 
£ 
B 
cr 
s 
CQ 
JO 
B 
(F 
IT. 
Granite and gneiss rocks 
5.94 
0.042 
0.008 
0.001 
0.106 
1.69 
3.0 
8 
Silurian rocks 
12.33 
0.051 
0.014 
0.001 
0.178 
1.84 
6.8 
15 
Devonian rocks and old red sandstones. 
25.06 
0.054 
0.012 
0.001 
0.764 
3.85 
12.0 
22 
Yoredale and mill stone, grits and 
coal measures 
21.91 
0.050 
0.014 
0.001 
0.393 
1.85 
13.1 
22 
Lias 
36.41 
0.073 
0.019 
0.001 
0.467 
2.48 
30.1 
7 
Oolites 
30.33 
0.043 
0.011 
0.001 
0.402 
1.55 
24.4 
35 
Chalk 
29.84 
0.044 
0.010 
0.001 
0.382 
2.45 
23.6 
30 
Fluvio-marine, drift, and gravel 
61.32 
0.086 
0.019 
0.001 
0.354 
2.76 
37.6 
10 
Summary.-Springs afford good sources of water supply for general 
domestic purposes, provided surface pollution is prevented. " Main 
springs " are preferable, because they are less liable to accidental con- 
taminations, but they generally contain a greater amount of the earthy 
salts, which give the water the quality of hardness. In other respects, 
especially in limestone regions, the water is clear, cool, and sparkling. 
Soap does not form a lather with hard water until the lime and mag- 
nesia have been precipitated in the form of curdy salts. If the hardness 
depends upon the presence of bicarbonates of lime and magnesia, it 
may be removed by boiling, because heat drives off the carbonic acid, 
and the less soluble carbonates are precipitated in the form of white 
flakes; this is called "temporary hardness," in contradistinction of 
what is called " permanent hardness," which is due to the presence of 
sulphates, and cannot be removed by boiling. 
At one time it was considered of the greatest importance to know 
exactly how many grains of each particular salt were contained in drink- 
ing water, but this is not so essential, for none of the earthy or alkaline 
salts usually found in water will do harm, unless present in sufficient 
quantities to constitute mineral waters, which will be detected by the 
disagreeable taste. 
What we do want to know in the matter of spring water is, whether 
it is free from soakage of the wastes of human life and occupation. It 
will be readily understood how, in a "land spring" issuing through 
very porous strata, like gravel, sand, or fissured rocks, the water may 
have been contaminated by manured fields, barns and stock-yards, cess- 
pools, and other waste products. This is especially liable to take place 
if the spring is situated at the base of a hill, on the top of which the 
polluting influences are going on. In such cases, the dip of the strata 
will enable us to estimate the probable amount of danger, and a bac- 
teriological examination of the water may also furnish valuable informa- 
tion. Thus Wolfhiigel found that in springs which were well protected 
against the infiltration of impurities, the number of germs contained in 
1 cc. was only 182; whilst in springs not so protected, they amounted 
to 2,730. 10 
3. Surface Water. (Streams, Rivers, Lakes, and Ponds.) 
The English River Pollution Commission, 6th Report, estimated that 
about half of the water descending as rain finds its way into the 
streams. 
In many mountainous districts in the United States and elsewhere, 
the water which flows off the hillsides is frequently collected by the 
construction of dams across the canon through which the stream flows, 
forming a so-called 11 impounding reservoir," from which the town or 
community may be supplied. My personal observations, and those of 
others, lead me to believe that it is always best to conduct the water in 
an open ditch to another reservoir before distribution, and to reject the 
water, unless absolutely necessary, which flows into the "impounding 
reservoir" during the early spring freshets. There is every reason to 
believe that apart from the greater amount of earthy matter contained 
in turbid streams, the amount of organic matter is also largely increased, 
and may even be a source of water-borne malaria. (See interesting 
Report of Dr. Smart, Am. Jour. Med. Sciences, January, 1878, p. 37.) 
Impurities.-The amount of mineral matter contained in streams, 
ponds, and lakes depends not only upon the character and amount con- 
tained in their original sources, but also upon the geological character of 
the country and the erosive power of the streams. The organic impuri- 
ties, as already indicated, are of greater interest to the sanitarian than 
the mineral constituents. The vegetation in ponds, lakes, and streams, 
and along their banks, supplies a certain amount of the organic matter, 
and the winds or rains sweep in more or less, but all this is insignificant 
when compared with the pollution by animal matter. 
The watercourses are the natural drainage channels of a country, and 
it is not surprising that the wastes of human life and occupation should 
find their way into the rivers. It is for this reason that the water of 
streams running through cultivated valleys, with cities, towns, and vil- 
lages on their banks, contain, often, a dangerous amount of organic 
matter, and we have the experience of Plymouth, Pennsylvania, to show 
that the excreta of a single typhoid patient washed into the stream 
which was used as a water supply, occasioned more than a thousand 
cases of typhoid fever. To show the contaminating influence of a town 
on a river, we may say that the River Maine, just above Wurzburg, con- 
tained only 177 mgr. per liter of organic matter, whilst immediately be- 
low the town it contained 470 mgr. per liter. 
Hueppe finds that river water contains micro-organisms of every 
description: infusoria, algse, fungi, bacteria, and often also metallic 
poisons. The number of germs varies with the purity of the stream, 
from 7 to 125,000 per ccm., and even as high as 10,000,000 have been 
observed. The amount of suspended matter carried by rivers varies at 
different times and places, but analysis usually reveals an increase as 
we descend the stream, as shown by the following table, prepared by Dr. 
Waller. (Parkes' Hygiene, vol. II, p. 410.) 11 
River. 
Place. 
Date. 
Mineral Mat- 
ter 
Organic and 
Volatile 
Total Solids... 
Chlorine 
Ammonia 
Albuminoid 
Ammonia... 
Hardness 
Analyst. 
Mississippi 
Minneapolis, Minn 
1877 
18.6 
1.1 
0.003 
0.015 
S. F. Peckham. 
Mississippi 
St. Louis, Mo 
Aug., 1873 
240.1 
4.2 
244.3 
1.21 
0.002 
0.068 
11.47 
D. V. Dean. 
Mississippi* 
St. Louis, Mo 
Aug., 1873 
45.04 
2.1 
47.14 
0.8 
0.011 
0.048 
8.22 
D. V. Dean. 
Ohio 
Cincinnati, 0 
1880 
14.2 
C. H. Stuntz. 
Ohio 
Louisville, Ky 
11.7 
0.6 
trace. 
- 
T. C. Van Nuys. 
Ohio 
Evansville, 1ft 
1880 
18.6 
0.9 
0.012 
T. C. Van Nuys. 
White 
Indianapolis, Ind. 
1880 
28.0 
0.4 
0.003 
0.003 
7.86 
T. C. Van Nuys. 
Cumberland 
Nashvilfe, Tenn. 
Sept., 1876 
- 
13.80 
0.3 
0.000 
N. T. Lupton. 
Cape Fear 
Wilmington, N. C. 
Aug., 1881 
9.30 
1.2 
5.6 
0.4 
0.008 
0.016 
6.00 
W. R. Nichols. 
Hudson 
Albany, N. Y 
Mar., 1872 
10.5 
0.52 
0.010 
0.019 
C. F. Chandler. 
Hudson 
Pough'keepsie, N.Y. 
Nov., 1877 
10.40 
1.7 
12.1 
- 
W. R. Nichols. 
Hudson* 
Poughkeepsie, N. Y. 
Nov., 1877 
5.702 
1.678 
10.1 
0.3 
0.010 
0.018 
3.21 
W. R. Nichols. 
Croton 
New T ork, N. Y 
1872-1882 
7.380 
0.001 
0.012 
E. Waller. 
Schuylkill 
Philadelphia, Pa. 
July, 1881 
5.28 
2.58 
12.01 
0.56 
0.002 
0.012 
8.6 
H. Leffmann. 
Passaic 
Falls, N. J 
July, 1872 
7.86 
0.43 
0.040 
0.040 
H. Wurtz. 
Passaic 
Belleville, N. J. 
July, 1872 
7.36 
1.95 
9.31 
0.47 
0.049 
0.085 
H. Wurtz. 
Analyses of Waters of Rivers in the United States. (Results in parts per 100,000.) 
* Filtered. 12 
Self-Purification of Rivers.-A study of the above table indicates that 
rivers near their source always contain a less amount of organic and 
mineral matters than after they have made a long run and received the 
drainage from a densely settled region. It is self-evident that a river, 
after it receives the sewage of a number of towns, cannot be as pure as 
before, and the question naturally arises, Can a river once polluted with 
sewage ever be a safe source of supply below the source of pollution? 
The question of "self-purification of streams" has been earnestly 
studied, especially in England, and it may be considered as still unset- 
tled. It is, however, conceded that a certain degree of purification is 
possible by natural means, viz.: 
1. Dilution of the sewage with clean or unpolluted water which empties 
into the stream along its course. 
2. By deposition of the suspended matter, carrying with it some of the 
organic material. 
3. By the agency of organisms in the water, as fish, water-plants, 
algse, and infusoria, which require organic matter for their food. 
4. By the micro-parasites or bacteria of nitrification, which bring about 
oxidation of organic matter, and then consume it. 
5. By the chemical affinity of certain bodies, by which dissolved and 
noxious substances are rendered insoluble; as, for example, the effect of 
sulphuretted hydrogen on certain soluble metallic salts. 
Of these factors, Uffelmann considers the influence of the micro- 
organisms in the process of oxidation of the greatest importance, since 
his experiments clearly show that the mere presence of oxygen in water 
without the bacteria of nitrification does not lead to a perceptible dimi- 
nution of organic matter. 
The rapidity of oxidation is influenced by the volume of organic 
matter present, the temperature of the water, the distance of the run, 
the rapidity of the current, and the character of the river-bed. It is 
perfectly natural that a rapid mountain stream going over bowlders 
and rocks should have a better opportunity for aeration than when the 
current is sluggish. 
The various factors named are calculated to purify the water in our 
streams, provided we give them a chance. This is still true in our own 
country, but with increasing settlements it is possible that practically 
here, as in England, the pollution of our streams will almost become 
continuous from their sources to their mouths. Whilst Dr. Tidy and 
some other eminent chemists believe that a flow of even ten or twelve 
miles is sufficient to free a river of all trace of sewage contamination, 
an outbreak of enteric fever in a hospital using river water was traced 
to a barracks twenty-five miles up the stream. (Mass. State Board of 
Health Rep., 1876, p. 284.) 
Lake Water.-In many cities a lake constitutes the general water sup- 
ply, and for the most part a very pure supply is thus obtained, as shown 
by the following table taken from Dr. Waller's article on water (Parkes' 
Hygiene, vol. II, p. 410): 13 
Place. 
Analyst. 
Date. 
Organic and 
Volatile. 
Mineral. 
Total 
Solids. 
Hardness. 
Lake Michigan 
Chicago, Ill. 
Blaney 
1859 
1.81 
9.63 
11.44 
3.00 
Lake Erie 
Cleveland, 0. 
Cassel 
February, 1866.... 
1.10 
8.23 
9.33 
Lake Ontario 
Toronto, Canada 
Croft... 
February, 1878 
0.77 
11.73 
12.50 
Lower Chain Lakes 
Halifax, Nova Scotia 
Lawson 
September, 1878... 
3.83 
3.49 
7.32 
0.84 
Lake Massabesic 
Manchester, N. H 
Plymouth, Mass 
Hayes 
June, 1869 - 
2.77 
1.93 
4.70 
South Pond 
Nichols 
June, 1877 
1.40 
1.60 
3.00 
0.34 
Watuppa Pond 
Lake Konomoc 
Fall River, Mass 
Appleton 
Nichols 
1870 
1.43 
1.67 
3.10 
New London, Conn. 
December, 1879... 
1.20 
1.60 
2.80 
0.93 
Artificial Lake 
Norwich, Conn. 
Silliman 
January, 1873 
1.16 
2.00 
3.16 
Lake Owasco 
Auburn, N. Y. 
Chandler 
1876 
1.20 
15.80 
17.00 
. 8.7 
Green Lake 
Syracuse, N. Y 
Chandler 
January, 1871 
1.20 
14.14 
16.34 
Reeds Lake 
Grand River, Mich 
Kedzie 
August, 1872 
much. 
12.86 
21.00 
Blue Lakes 
San Francisco, Cal 
Falkenan 
April, 1875 
- 
Examinations of Water from Lakes and Ponds. (Results given in parts per 100,000.) 14 
Glasgow is supplied from Loch Katrine, 34 miles from the city. The 
water contains only 2| grains of solid matters per gallon, and is regarded 
as very soft and pure. The saving in soap alone since it replaced the 
polluted River Clyde, in 1859, is estimated at 36,000 pounds sterling 
per annum. 
Finkener's analyses of European lakes indicate that some contain 
considerable quantities of chlorine, ammonia, and nitrates. 
According to Hueppe, the number of micro-organisms contained in 
1 cc. of lake water varied from 8 to 1,384. 
Summary.-From the evidence, we may conclude that rivers and 
streams are always purer near their sources, and when not contaminated, 
they are good sources of supply. After receiving sewage, a stream may, 
under favorable conditions, undergo a certain degree of self-purification, 
but we cannot rest satisfied that dangerous contamination does not 
exist, and such waters cannot be recommended for dietetic purposes, if 
any better supply can be obtained. The water supply from ponds and 
lakes, when not stagnant,, but undergoing frequent changes, may be re- 
garded as good, provided it has not been contaminated by the sources of 
impurity already referred to. No surface water, whether from streams, 
ponds, or lakes, should be used for dietetic purposes until the suspended 
matter is removed by subsidence or filtration, or both. We shall learn 
hereafter that the chemical analysis of a drinking water gives no posi- 
tive information concerning its wholesomeness. The organic matter in 
a water may be harmless or dangerous. On general principles, we may 
infer that whenever there is much organic matter there is a greater like- 
lihood of the presence of disease germs. 
4. Well Water. 
It has been estimated that about one fourth of the rainfall of a cer- 
tain locality soaks into the ground, and may be obtained by sinking 
wells. There are, practically speaking, but two kinds of wells: "shal- 
low" and "deep," according as they are less or more than fifty feet in 
depth. 
(a) Shallow wells are those sunk into superficial, porous beds over- 
lying an impermeable stratum of clay or rock, commonly called " hard- 
pan," and which tap the underground water held up by these formations. 
They supply the same quality of water yielded by the "land springs" 
of the respective locality, and are therefore subject to the same contami- 
nations. The rural population, and for that matter many people in 
towns and cities, derive their water almost exclusively from shallow 
wells (pump water). Wherever a public supply from unpolluted 
sources exists, the use of shallow wells should be interdicted, as it is 
simply impossible to prevent contamination. 
The English River Pollution Commission, 6th Report, stated that 
in their experience shallow wells are almost always polluted by sewage 
and animal matters of the most disgusting origin. "The common prac- 
tice in villages, and even in many small towns, is to dispose of the 
sewage and to provide for the water supply of each cottage or pair of 
cottages upon the premises. In the little yard or garden attached to 
each tenement or pair of tenements, two holes are dug in the porous 
soil; into one of these, usually the shallower of the two, all the filthy 15 
liquids of the house are discharged; from the other, which is sunk below 
the water-line of the porous stratum, the water for drinking and other 
domestic purposes is pumped. These two holes are not infrequently 
within twelve feet of each other, and sometimes even closer. The con- 
tents of the filth-hole or cesspool gradually soak away through the sur- 
rounding soil and mingle with the water below. As the contents of the 
water-hole, or well, are pumped out, they are immediately replenished 
from the surrounding disgusting mixture, and it is not, therefore, very 
surprising to be assured that such a well does not become dry, even in 
summer. Unfortunately, excrementitious liquids, especially after they 
have soaked through a few feet of porous s.oil, do not impair the palata- 
bility of water, and this polluted liquid is consumed from year to year 
without a suspicion of its character, until the cesspool and well receive 
infected sewage, and then an outbreak of epidemic disease compels atten- 
tion to the polluted water. Indeed, our acquaintance with a very large 
proportion of this class of potable waters has been made, in consequence 
of the occurrence of severe outbreaks of typhoid fever amongst the per- 
sons using them." (English River Pollution Commission, 6th Report.) 
What is true of England is under like circumstances true of this 
country. One reason why our people do not avoid the dangerous prox- 
imity of cesspools and wells, is the widespread belief that water becomes 
purified by filtration through the soil. Whilst this is true to a limited 
extent, there is abundant evidence to show that organic matter may 
percolate into wells from quite a distance. Very few persons, in the 
first place, realize how extensively soil pollution can take place, and 
fewer still know how far contaminated water may travel before it reaches 
a well. In some instances, which will be referred to later, the wells 
were infected from a distance of 30, 60, and even 100 feet. A case is on 
record in. which a well was polluted by gas works 1,000 feet distant. 
(Fisher, Dingl. Polyt. Jour., ccxi, 139.) 
A well usually drains an area all around it in the form of a circle, 
and this distance, or radius of the circle drained by the well, is generally 
expressed in terms of the depression. Field and Peggs state that in fine 
sands and gravels, which offer considerable resistance to the passage of 
water, the distance varies from 15 to 39 times the depression. In the 
chalk, where fissures facilitate the passage of water, the distance is 57 
times the depression. In very coarse gravel, which allows free passage 
of water, the distance is from 68 to 160 times the depression; and in the 
new red sandstone, where extensive fissures exist, the distance is 143 
times the depression. These results are founded on experiments made 
abroad by sinking borings at different distances around the well, but 
require confirmation by more extended observation. (Parkes.) 
The number of micro-parasites in well water varies, according to 
Hueppe, from 10 to 75,000 per 1 ccm. He found- 
In chemically good well water 
5 to 52 per 1 ccm. 
In chemically doubtful well water 
12 to 8,160 per 1 ccm. 
In chemically bad well water 
0 to 11,960 per 1 ccm. 
In wells of densely populated communities 
0 to 75,000 per 1 ccm. 
Waller's table of the results of the analyses of the water of wells, two 
of them of fair quality and two much polluted, is also presented: 16 
Well Waters. 
(Results given in parts per 100,000.) 
Fair. 
Polluted. 
Appearance 
Faintly 
turbid; 
colorless. 
Clear; 
light 
bluish. 
Clear; 
light blue. 
Turbid; 
yellowish. 
Odor 
none. 
slight. 
sweetish. 
foul. 
Chlorine in chlorides 
0.527 
0.877 
15.114 
24.103 
Phosphoric acid in phosphates 
none. 
none. 
trace. 
much. 
Nitrogen in nitrates and nitrites 
0.091 
0.252 
11.53 
4.035 
Nitrites 
none. 
none. 
trace. 
much. 
Free ammonia 
Albuminoid ammonia 
none. 
0.004 
0.0004 
none. 
0.0072 
0.0022 
0.620 
Oxygen absorbed 15 minutes 
0.0244 
none. 
0.028 
0.265 
Oxygen absorbed 3 hours 
0.0244 
0.0054 
0.028 
0.337 
Hardness before boiling 
1.874 
19.23 
51.7 
32.019 
Hardness after boiling 
1.106 
3.72 
39.2 
30.935 
Organic and volatile matter 
1.60 
1.50 
44.9 
59.40 
Mineral matter 
5.70 
22.90 
157.10 
127.70 
Total solids on evaporation 
7.30 
24.40 
202.00 
187.10 
It is very evident that well water contains a larger amount of the chlo- 
rides, nitrogen in the form of nitrates and nitrites, also a larger amount 
of organic matter and germs, than springs and ordinary ground water. 
The respective amounts are largely influenced by the character of the 
soil, construction of the wells, and as regards the presence of germs, 
also by the temperature of the water and the use of the wells. It has 
been determined that cold water (about 40°), proper protection of the 
walls of the well, and constant use, furnish the least number of micro- 
organisms. This would indicate that they gain access, not so much from 
the ground water, as from the upper strata of the soil, and especially along 
the walls exposed to the action of the air. The chemical composition 
of the water would naturally influence the multiplication of germs, as 
they all require a proper pabulum for their development. 
(6) Drive wells are made by driving an iron tube with a steel nozzle 
and perforations at its lower end, for the passage of water into the 
ground. They are rarely more than 30 feet in depth, and furnish a 
quality of water similar to that obtained from wells of like depth. They 
are, however, preferable, because the water is less liable to organic pollu- 
tion, and if an impervious stratum intervenes between the surface of 
the soil and the ground water, a very pure quality may be obtained. 
(c) Deep wells are generally not less than 100 feet in depth, and 
nowadays are usually made by boring (artesian wells) through regular 
geological strata. They pass through a superficial porous bed and an 
underlying impermeable stratum to reach water-bearing strata at greater 
depths. The water of deep wells usually travels a long distance, and 
the outcrop of the water-bearing strata on the surface may be many 
miles from the spot at which the well is sunk; but the position of the 
strata has an important influence on the quality of the water in relation 
to filtration from the surface. Dr. Waller has examined the wells of 
Manhattan Island, varying in depth from a few feet to 1,000 feet or more, 
and found that none of them " could be regarded as safe for household 
purposes. The strata on the island stand an angles varying from 80° 17 
to 90c with the horizon, or nearly vertical, and as the tendency of the 
water is to follow the direction of the strata, a well sunk at one point, 
however deep, draws its supply from the water which has penetrated the 
surface not very far off, and in such a densely populated district all the 
water soaking through the ground becomes practically sewage, and is in 
the highest degree dangerous for use. London and Paris can sink their 
artesian wells and obtain wholesome water, since they are situated in 
geological basins, and the water from these wells has filtered into the 
water-bearing stratum from considerable distance outside of the city 
limits; but New York is not so favorably situated." A similar pollution 
may, of course, occur through rocks containing many fissures, even 
though they may be nearly horizontal formations. The reports from 
Rostock and Erlangen show that artesian water at a depth of 300 to 400 
feet may be unfit for dietetic purposes. Generally speaking, the water 
supplied by deep wells is remarkably free from organic impurities; the 
chlorides, nitrates, nitrites, and CO2 are present in diminished quantity, 
but chalk and magnesia are often in excess. The number of micro- 
organisms in artesian wells, according to Hueppe, is from 15 to 144 per 
1 com., and water from chalk formations is usually free from germs. 
The temperature of artesian wells varies with their depth. The well at 
Grenelle is 1,800 feet deep, and yields 656 gallons of water per minute, 
with a temperature of about 80°. 
5. Marsh Water. 
This water is ground and rain water, which stagnates in swampy sub- 
soil; it always contains a large amount of vegetable matter, sometimes 
as high as 12 to 40 grains per gallon. The mineral ingredients depend 
upon the character of the surroundings; calcium and sodium, in combi- 
nation with carbonic and sulphuric acids, and chlorine, especially in 
salt marshes, are the most frequent. The water is unfit for drinking 
purposes, and the brackish water is especially favorable for the develop- 
ment of the germs of malarial fevers. 
6. Ocean Water. 
This water is especially rich in saline matter, the chlorides of sodium, 
and the chlorides and sulphates of magnesia; it contains very little 
ammonia, nitrates or nitrites. On account of the chlorides, water from 
wells near the sea is often quite brackish, although the organic matter 
may not be very large. At Landgward Fort, water from a boring 150 
feet deep yielded more than 500 grains of solids and 380 grains of 
chlorides; the mean of six other samples was 165 of total solids and 35 
of chlorides per gallon. 
Summary.-From what has been said on the subject of wells, it is 
clear that they require special sanitary supervision. The depth of a 
well has less to do with the purity of the water supply than the preven- 
tion of surface and general soil pollution. In locating a well, it is neces- 
sary to carefully note: (1) Its position and depth in relation to cess- 
pools and other sources of pollution, the kitchen drain, barnyard, stables, 
cemeteries, manufactories, etc. (2) The character of the soil in which 
the well is sunk in reference to porosity; the lay of the underlying strata. 
2k 18 
It would be obviously dangerous, as remarked by Waller, to place a well 
between a cesspool and the sloping margin of a stream, since the drain- 
age naturally tends toward the stream bed. (3) The distance of a well 
from possible sources of pollution should be from 100 to 160 times the 
depression of the water in the well likely to be produced by pumping. 
All wells should be walled in, closed over, supplied with an iron pump, 
and protected by a coping to prevent contamination. The clear, spark- 
ling, and palatable character of well water is no indication of its purity, 
and should not mislead us when the surroundings are suspicious. The 
River Pollution Commission advised the closing of all the wells in London 
except three, which were favorably placed; and Fanning considers the 
danger from contamination in towns where there may be a house every 
100 feet very great; but everywhere, even in isolated farm houses, we 
should feel the necessity of constant attention to the water supply. 
The Hygienic Importance of Water. 
We have already referred to the fact that water is of prime necessity 
to man. It must be remembered that about 75 per cent of the human 
body consists of water, and the food proper to nourish one should con- 
tain about 81.5 per cent of water. "Solid food" contains, roughly 
speaking, from 50 to 80 per cent of water, and thus to make up the nec- 
essary amount of water, and to replace the loss eliminated by the kidneys, 
lungs, and skin, a certain quantity must be drunk in addition to the 
food. A healthy man weighing 154 pounds requires every twenty-four 
hours about 5-j pints of water in some form or other. When the amount 
of water in the system is diminished by about 1 per cent of the whole, 
the sensation of thirst is felt, which we usually allay by imbibing the 
needful amount. 
But like all good things, water may be used and abused; it may injure 
the system if taken in too large quantities, or if too hastily swallowed, 
or if taken too cold or too hot. If taken too freely, it will dilute the 
gastric secretions, and thus impair the digestive processes. Hasty 
drinking, especially if the water is too cold, may produce cardialgia, 
increased peristaltic action, colic, and, if swallowed when the body is 
overheated, acute gastric catarrh, and other mischief may result. Luke- 
warm water is liable to induce nausea, whilst hot water, instead of curing 
dyspepsia, is more apt to produce that disease, or cause inflammation of 
the gastric mucous membrane; warm water generally produces a feeling 
of agreeable warmth. 
The degree of hardness of the water in relation to health is still a 
matter of dispute. It has been claimed that the presence of the salts of 
lime and magnesia may produce in some persons digestive derangements, 
and even lead to the formation of renal and vesicle calculi; but whilst 
this is not proven, we know that hard water is objectionable for culinary 
and washing purposes, and causes a great waste of soap. Very soft water 
is not free from objections, however, as it readily attacks lead. 
Aeration of the water is of importance, since we all know how flat 
boiled and distilled waters taste. The carbonated waters are especially 
agreeable, and exert slightly stimulating properties upon the nerves of 
the digestive tract. Jaworsky, quoted by Uflelmann, claims that they 
favor the secretion of pepsin. 19 
Ammonia, nitrates and nitrites, which are the oxidized residues of 
organic matters in the water, unless present in excess are not believed to 
be injurious to the system. Bartholow, Wood, and Hilgard tell us, how- 
ever, that the daily introduction of ammonia into the stomach produces 
more or less irritation of the mucous membrane, and dyspepsia is almost 
sure to supervene. Circumstances may arise, therefore, to direct our 
attention to the estimation of ammonia in the water supply; the pres- 
ence of nitrites is always suspicious. 
The presence of non-oxidized organic matter and of micro-parasites in 
the water is of great importance to the sanitarian. If this matter is of 
vegetable origin, it is often quite harmless, unless present in considerable 
quantity. Organic matters of an animal or excrementitious character 
are dangerous, as well as disgusting. We have pointed out the various 
sources of vegetable matter in water, from swamps, forests, vegetation, 
and dust, and have spoken of the wastes of human life and occupations, 
cesspools, stables, slaughtering-houses, etc., as the most common sources 
of animal pollution. We also know that the atmosphere contains bac- 
teria, many of which are the agents of decomposition, and select dead 
animal and vegetable matter, upon which they feed and proliferate, as 
their lurking places, and, clinging to such matter, often find their way 
into surface and other waters. When they are present in moderate 
numbers, under ordinary circumstances they are not at all harmful to 
the consumer of water, for the few thousand vegetable cells which we 
call bacteria may be just as harmless as a few hundred vegetable cells of 
larger size; but if the water has been derived from an impure source or 
becomes stagnant, the bacteria may proliferate in such large numbers as 
to produce serious disorders of the digestive tract. We do not know to 
what extent the ordinary harmless bacteria may be present before the 
water would become harmful, but the limit has been placed by Prudden 
at from 300 to 500 to the teaspoonful. 
Now, whilst we know that diarrhoea, cholera morbus, and dysentery 
have been caused by water containing a large amount of organic matter, 
and in consequence also a large number of bacteria, it is not yet known 
whether the organic matter, or the bacteria, or the life products of bac- 
teria, called ptomaines, produce the diseases spoken of, or whether they 
are invariably caused by the presence of a specific pathogenic germ. It 
would appear that ptomaines can induce intestinal catarrh, for Brieger 
has shown that the enteritis of Asiatic cholera is most likely caused by 
cadaverin and putrescin, and Vaughan regards tyrotoxicon, another 
ptomaine, as the cause of cholera infantum. The presence of these 
poisonous alkaloids has not yet been demonstrated in ordinary water, 
but there is much reason for believing that ptomaines are generated 
whenever the water is charged with decomposable organic matter and 
bacteria. On the other hand, we do know that certain disease-producing 
bacteria may be present in the drinking water. In fact, the specific 
micro-organisms of certain diseases which are often spread through the 
agency of water have been actually found in water and isolated. 
In the first place, Meade, Bolton, and others have shown that the 
bacilli of typhoid and the coma bacilli may retain their vitality for a 
certain time in water especially rich in organic matter, and secondly, 
Koch found his cholera coma bacilli in a pond which supplied Calcutta 
with water, and they luxuriated particularly well in the suspended par- 
ticles of organic matter. Mors, Michael, Beumer, Chantemesse, Vidal, 20 
and others have demonstrated the presence of typhoid bacilli in wells 
during the prevalence of enteric fever, and in addition to this we have 
such an array of epidemiological facts connecting the spread of typhoid 
fever and cholera with a contaminated water supply, that the advocates 
of the "germ theory" feel fully fortified in their position. Professor 
Pettenkofer and his adherents, however, reject the "drinking water 
theory," and maintain that the character of the soil, together with various 
conditions induced in it by meteorological changes ("telluric theory"), 
are the principal factors in the production of these diseases. We do not 
claim that a polluted water supply is the only possible means of spread- 
ing the infectious germs of these diseases, but there is sufficient evidence 
on record that not only the diseases already mentioned, but also diar- 
rhoea, dysentery, malarial and yellow fevers, and diphtheria have been 
traced to contaminated drinking water. 
Goitre appears to be due, in many instances, to the water used for 
drinking, but as yet we are completely in the dark as to the exact cause. 
Some attribute it to an excess of the earthy salts; others to compounds 
of bromine and fluorine, or to a deficiency of iodine; whilst Bircher 
attributes it to an alga, the navicula. 
Entozoa.-There is no doubt that certain parasites, their embryos or 
eggs, gain access into the system through the water supply. They are: 
Taenia solium, Bothriocephalus latus (tape-worms), Ascaris lumbricoides 
(round worms), Oxyuris vermicularis (thread worms), Filaria sanguinis 
hominis, the embryos of which are sucked from the blood by mosquitoes, 
and then transferred to water, Bilharzia haematobia, Distoma hepaticum 
(liver fluke of sheep), and Distoma ringeri, believed to be the cause of 
endemic haemoptysis in Eastern Asia, and finally the Filaria dracun- 
culus, or guinea worm, which has been known to penetrate the sub- 
cutaneous tissues of bathers. 
The possibility that parasites and disease germs may also gain access 
into the system during the washing of vegetables (like lettuce and 
radishes), fruits, and meats should not be overlooked, and many dis- 
ease germs may be spread by the wash-water from infected clothing and 
persons, the cleaning of habitations, and the sprinkling of public high- 
ways. 
Metallic poisoning may be caused by the waste waters of factories and 
metalliferous mines gaining access to the water supply, or by the absorp- 
tion of metals from utensils, water pipes, and tanks. In the case of 
lead poisoning of Louis Phillips' family at Clairmont, seven tenths of a 
grain of lead was found in each gallon of water. Similar cases have 
been reported in France and Germany. 
Characteristics of a Good Water. 
1. The water should be clear, colorless, and odorless, even when 
warmed. 
2. A temperature between 45° and 60° is the most agreeable for 
drinking purposes. A lower temperature, such as the pernicious ice 
pitcher supplies, should be avoided. 
3. It should be agreeable to the taste, having a slight pungency from 
the presence of oxygen or carbonic acid; but the palate cannot be 
depended upon, as water containing dangerous forms of animal matter 
is often pleasant enough to the taste. 21 
4. It should be free from suspended matters, infectious germs, and 
even the suspicion of the presence of such germs. 
5. It should be free from metallic contamination, and the degree of 
hardness should be small for cooking and drinking purposes; the extreme 
limit is set by some as high as 30 parts per 100,000. 
The solids remaining on evaporation, according to Waller, should not 
exceed 50 parts per 100,000 (about 30 grains per gallon). Less than 
two parts of organic matter is regarded as admissible, but the quality of 
the organic impurity is much more important than the quantity. 
The presence of phosphates in any marked quantity, unless properly 
accounted for, is indicative of animal pollution, and strongly suggestive 
of infectious matter. This is also true of chlorine in chlorides, if not 
accounted for by natural causes: 5 parts per 100,000 (3 grains per gal- 
lon) is the extreme limit assigned by some. 
The amounts of ammonia and nitrates should be quite small, while 
nitrites should be entirely absent, although it does not necessarily follow 
that they are the products of harmful organic matter. 
Classification of Waters 
yls Regards Quality.-The English River Pollution Commission (6th 
Report) present the following classification of waters "with respect to 
wholesomeness, palatability, and general fitness for drinking and cook- 
ing:" 
Wholesome. | 'water. } Very palatable. 
Suspicious K"SeTter' ( P"- 
b P s' ( Surface water from cultivated land. ) 
n„River water to which sewage gains access. > Palatable. 
Dangerous. ] Shanow well water. | 
This classification is quite in accord with clinical facts. 
As Regards Quantity.-The water supply must not only be of good 
quality, but also sufficient in quantity to meet the requirements of clean- 
liness of our bodies, clothing, homes, streets, and public resorts. Parkes 
estimates the average daily requirements per head as follows: 
Fluids as drink 
Gallons per head daily. 
0.33 
Cooking 
0.75 
Household. 
Personal ablution 
Utensil and house washing 
.... 5.00 
3.00 
Clothes washing (laundry) 
3 00 
Water-closets 
Trade and manufacturing 
5.00 
Municipal. ■ 
Cleansing streets • 
Public baths and fountains 
Flushing and cleansing sewers 
.Extinguishing fires 
1 5 00 
Total 
27.08 
A supply of 30 gallons daily per man would appear a sufficient 
amount for comfort and health. Provision must also be made for live 
stock, stables, etc. A horse requires about 16 gallons, a cow 10 gallons, 
and pigs about 5 gallons a day. 22 
Examination of Water for Sanitary Purposes. 
This may be accomplished by a physical, microscopical, and biological 
examination, and chemical analysis of the water. In our present state of 
knowledge, it is difficult to say which of these tests is of the greatest 
importance to the sanitarian, and whilst we may conclude that a bac- 
teriological examination of the water will reveal the most important 
information, it is also true that one examination should supplement the 
other. As most of the examinations are made by experts, we shall pre- 
sent simply a brief schedule, and refer to the text-books for details. 
I. Taking Samples. 
In taking samples, it is of the utmost importance that it should be 
received in perfectly clean glass vessels; demijohns of 1 to 2 gallons capac- 
ity are the best. If the water is taken from a spring, pond, or river, 
the demijohn should be placed below the surface before it is filled; if the 
water is too shallow for this purpose, receive it in a smaller vessel and 
fill the demijohn from the latter. In drawing from pipes, a portion should 
be allowed to run to waste, in order to obtain an average supply. In 
towns, samples should be obtained direct from the mains, as well as from 
the houses. The bottle should be stopped with a glass stopper or a new 
clean cork, tied in and sealed, and transmitted at once to the analyst, 
duly labeled as to source of the water, the character of strata, character 
of the wells and springs, possibilities of impurities, meteorological con- 
ditions, droughts, excessive rainfall, prevailing diseases or the existence 
of any disease supposed to be connected with the water supply, aYid any 
remarks tending to show the reason for desiring an analysis. 
II. Physical Examination. 
1. Color.-The water should be examined in a two-foot clear white 
glass tube, standing on a white surface. The best samples are of a 
bluish or grayish tint; a greenish tint suggests vegetable contamina- 
tion, whilst light brown or yellow colors are indicative of sewage con- 
tamination, but may also be due to peat, or the salts of iron. 
2. Clearness.-The water in the glass tube or globe should be shaken. 
The purest waters are clear, bright, and sparkling, but this may also be 
the case in polluted, shallow well water. 
3. Odor.-This is best determined by placing the water in a bottle 
with a narrow neck, and heating it to 104° or 112° F. Hydrogen sul- 
phide, ammonia, and other gases of putrefaction may thus be recognized. 
4. Taste.-This is an uncertain indication, and is largely influenced 
by the temperature of the water, and the presence or absence of gases. 
Iron may be tasted in very small quantities. Polluted or badly tasting 
waters should be rejected. 
5. Temperature of the water can readily be determined by means of 
accurate thermometers placed in the original source, or in water after 
the amount contained in the house pipe has been allowed to run to 
waste. 
Whilst the physical examination of the water affords no reliable evi- 
dence of its purity, it is of importance when no other examination can 
be made, or in connection with other methods. 23 
III. Chemical Analysis of Water. 
We have already, on p. 21, referred broadly to the limit at which 
certain constituents of water may be present without impairing the 
safety of a drinking water. 
A qualitative examination of the solids dissolved in water alone is of 
no special value in judging the purity of a water, as the same constituents 
may exist in perfectly pure waters. It is far more important that we 
should know the amounts of each constituent in order to determine 
whether they are in excess or not. The chemist employs almost univers- 
ally the French metric system in quantitative analysis, and the results are 
usually expressed as parts per 100,000, or as parts per million, which is 
the same thing as milligrammes per liter. [A liter of water is equal to 
1,000 cubic centimeters, and each cubic centimeter of pure water at 
4° C. weighs one gramme (=1,000 milligrammes).] Results are also 
sometimes expressed as grains per gallon, but this is oftentimes mislead- 
ing, especially when the report does not specify the gallon used: United 
States or imperial (English). The latter weighs 70,000 grains, and 70 cc. 
of water weigh 70,000 milligrammes; the quantity 70 cc. is a miniature 
gallon, and the results in milligrammes obtained by using 70 cc. may 
also be expressed as grains per gallon. If grains per gallon are multi- 
plied by 10 and divided by 7, parts per 100,000 are obtained; parts per 
100,000 may be converted into grains per gallon by multiplying by 7 
and dividing by 10. The metric system should be adopted to the 
exclusion of all others. 
1. Determination of Total Solids.-Evaporate 70 cc. of the water to 
dryness in a weighed platinum or porcelain dish, over a water bath, and 
weigh the residue thus obtained. This residue may then be heated to 
redness over a flame; the organic matter and volatile salts are driven 
off by the heat (note the loss of weight); the residue which remains con- 
sists entirely of mineral matters. 
2. Determination of Organic Matter.-The above test for determining 
the amount of organic matter is altogether unreliable. Some of the 
organic matter may be lost on evaporation, or it may not be all driven 
off by ignition; again many of the mineral constituents may be decom- 
posed with partial loss (carbonate of lime loses its carbonic acid and 
becomes quicklime); other mineral salts, as potassium chloride, may be 
partially or totally volatilized. Even the best methods of estimating 
the amount of organic matters only give approximate results; they are: 
(a) The Permanganate Process.-Potassium permanganate dissolves 
readily in water and imparts a strong red-violet tint; it also parts with 
a large proportion of the oxygen it contains, affording colorless com- 
pounds in the presence of an acid. By this process, the oxidizable mat- 
ters in water are determined in terms of the oxygen required for their 
oxidation. These matters include oxidizable organic matters, nitrites, 
ferrous salts, and sulphuretted hydrogen; the latter can be dispelled by 
heating the water, and the salts of iron may be tasted, but are generally 
disregarded. 
To estimate, therefore, the oxidizable organic matters and nitrites, 
proceed as follows: Take 250 cc. of the water; add 3 cc. of sulphuric 
acid; drop in the permanganate solution (capable of yielding, in the 24 
presence of an acid, 0.1 milligramme of oxygen for each cc.) from a 
burette until a pink color is established; warm the water up to 140° F. 
(60° C.) and drop in more permanganate solution; if the color disap- 
pears when the temperature reaches 140°, remove the lamp and continue 
the addition of the permanganate until the pink color is permanent for 
from ten to fifteen minutes. Then read off the number of cc. used; mul- 
tiply by 0.1, to determine the milligrammes of oxygen required for the 
oxidation of oxidizable matters, and multiply by 4, to get the amount per 
liter. Example: 250 cc. of water with 3 cc. of sulphuric acid required 
3.5 cc. of permanganate to give permanent color. 3.5 X 0.1 X 4 = 1.4 
milligramme of oxygen per liter required for total oxidizable matter, 
1.4 X 0.1 - 0.14 per 100,000. 
If the acidified water, as above given, is boiled for twenty minutes 
before adding the permanganate solution, the nitrous acid is driven off, 
and on cooling to 140° F., the oxidizable organic matter in terms of 
oxygen required for its oxidation may be determined. The nitrous acid 
in terms of oxygen required for its oxidation may be readily determined 
by calculation of the difference between the results of the two preceding 
processes. Each milligramme of oxygen represents 2.875 milligrammes 
of nitrous acid; we must, therefore, multiply the difference by this factor, 
and the result is nitrous acid in milligrammes per liter. 
The permanganate process is simple and convenient, but is not enti- 
tled to implicit faith, for we do not know how much of the organic 
matter in a given specimen of wrater is oxidizable by an acid perman- 
ganate solution and how much is not. Nitrous acid is considered the 
first stage in the nitrification of organic matters and ammonia, and 
suggests, therefore, incomplete oxidation and possible danger. 
(5) The Albuminoid Ammonia Process was proposed by Wanklyn and 
others, because of its simplicity: Add to the water remaining in the 
flask after the distillation of 150 cc. for the estimation of ammonia 
(free and saline), p. 25, 50 cc. of a strongly alkaline solution of perman- 
ganate, and continue the distillation, each 50 cc. of distillate having its 
ammonia estimated until no more comes over. The ammonia is the 
result of the action of the caustic permanganate solution at a boiling 
temperature on the nitrogenous organic matters (albuminous bodies, 
believed to be the favorable abode of disease germs); hence, this form of 
ammonia has been called albuminoid ammonia. Urea is not acted on 
by the solution, but this substance is not found in sewage, unless very 
fresh, and is never found in sewage-polluted water. All the free or 
saline ammonia must first be driven off by distillation before testing for 
" albuminoid ammonia." 
(c) The Organic Carbon and Organic Nitrogen Process (Franklands). 
In this process the water is evaporated and the residue burnt with oxide 
of copper. Nitrogen and carbonic acid gases are set free from the 
organic matters and their volumes respectively measured and reported 
as " organic carbon " and " organic nitrogen." The ratio of carbon to 
nitrogen for animal matter is given as 3.1, and 8.1 for vegetable matter. 
Good drinking Water should not contain over 0.2 part of organic carbon 
and 0.02 of organic nitrogen per 100,000 of the water. The combustion 
process requires elaborate apparatus and skilled hands. 
In conclusion, the nitrate of silver methods of Leeds and Fleck may 
be referred to. Of all the tests referred to above, the permanganate proc- 
ess is as reliable as any; none of them are perfect, and none, as Uffel- 25 
mann justly observes, can distinguish the harmless from the dangerous 
character of organic matter-a fact of great importance in judging the 
safety of the water. 
3. Determination of Ammonia.-It is well known that urea, when it 
undergoes decomposition, is converted into carbonate of ammonia; 
hence, the ammoniacal odor of sewage. Ammonia will also be found in 
water polluted with sewage, unless the latter has percolated through a 
sufficient depth of soil to convert the ammonia by oxidation into 
nitrates and nitrites. Parkes tells us that a few pure deep-well waters 
from the chalk and greensand are found to contain excess of ammonia, 
but are otherwise free from organic matters, whilst sewage-polluted 
shallow wells not only contain an excess of ammonia, but also an 
excessive amount of organic matter. 
To estimate ammonia, place 500 cc. of the water in a retort connected 
with a condenser, and distill off about 150 cc. The first 50 cc. contain 
usually three fourths of the entire amount of saline and free ammonia 
thus driven off', so that if the quantity of ammonia in the first 50 cc. is 
estimated, it is only necessary to add a third of this amount to obtain 
the whole quantity present in half a liter of the water; but the method 
of estimating the ammonia in each 50 cc. of distillate as it comes over is 
to be preferred: add 2 cc. of Nessler's solution to each 50 cc. of distillate, 
and compare on a white surface the yellow coloration produced with 
that obtained from a measured quantity of the standard ammonium 
chloride solution, each cc. of which contains 0.01 milligramme of 
ammonia. If the colors correspond after three to five minutes, read off 
the number of cc. of ammonium chloride used; allow for the portion of 
distillate not used; multiply by 0.01, and then by 4; the result is milli- 
grammes of free ammonia per liter, or parts per million; dividing by 10 
gives parts per 100,000. 
4. Determination of Nitrates and Nitrites.-The presence of either or 
both of these compounds in water is suspicious, since they are the oxi- 
dized residues of nitrogenous or organic matter. Nitrates and nitrites 
are not found in fresh sewage, but are present in combination with lime, 
soda, potash, etc., in polluted streams and watercourses, and in the 
effluent subsoil waters from manured or sewaged land. When found in 
drinking water, they are generally the result of previous pollution either 
of the water itself or of the soil through which it flows, but we cannot 
tell when the pollution may have taken place, and for all we know con- 
tamination may still be going on. When found in deep wells or springs, 
their presence simply indicates complete purification of the water in its 
passage to the deep strata. This is wholly true of the nitrates; but if 
they are found in shallow wells in connection with nitrites (which repre- 
sent the transition state between ammonia and albuminoid compounds 
and the nitrates), and also find an excess of chlorine and ammonia, we 
may justly regard it as evidence of sewage or animal contamination. 
For the purpose of estimating the amount of nitrates, evaporate to 
dryness 10 cc. of the water in a small platinum dish. Add to this 
residue 3 cc. of a solution of sulphuric acid and phenol and two drops 
of pure hydrochloric acid, and then warm the dish for three minutes 
over the water bath. Pour the contents into a Nessler glass, and neu- 
tralize with caustic potash solution until effervescence ceases; then fill 26 
up with distilled water to the 50 cc. mark, and compare the depth of the 
yellow color produced with that of a test solution containing one milli- 
gramme of nitrate of potash in each cubic centimeter, to which the same 
reagents have been added. This process of comparison by depth of col- 
oration is known as " Nesslerizing." To express in terms of nitrogen as 
nitrates the result must be multiplied by 0.14 (Parkes). The indigo 
method of Marx Tromsdorff and the Tiemann chloride of iron method 
are commonly used in Germany. 
For the direct determination of nitrites a solution of metaphenylen- 
diamine is prepared, and also a dilute sulphuric acid, one part of strong 
sulphuric acid to two parts of water. One cc. of each solution is added 
to 100 cc. of the water, which is put in a Nessler glass; a red color is pro- 
duced. Another glass is placed alongside, and into it is put as much of 
a standard solution of potassium nitrite as may be necessary, making 
up the bulk to 100 cc. with distilled water; then add 1 cc. each of the 
sulphuric acid and the metaphenylendiamine. The remainder of the 
process is carried on much in the same way as ordinary Nesslerizing. 
The standard potassium nitrite should be 1 cc. = 0.01 milligramme of 
NO2. The number of cc. used gives the milligrammes of NO2 present 
in the sample of water. 
5. Determination of Chlorine.-As already stated, water in certain 
localities may contain chlorides in excess. Rain water contains 0.5 per 
100,000, and pure waters as high as 1.4 per 100,000. An increase beyond 
this, unless accounted for by salt-water strata or proximity to the ocean, 
is strongly indicative of animal pollution, since vegetable contamina- 
tion may exist without appreciable increase of the chlorides. Sewage 
derives the chloride of sodium mostly from the urine it contains, and, 
because of the great solubility of the salt, it is not readily removed by 
filtration through the strata. 
Place 100 cc. of the water to be examined in a white porcelain dish; 
add 1 cc. of potassium-mono-chromate solution (free from chlorine); 
drop in the standard silver nitrate from the burette, and stir after each 
addition; continue to drop until the chlorine, being all precipitated as 
silver chloride, a reddish color of silver chromate is just obtained. The 
nitrate of silver solution must be of a strength that 1 cc. will exactly 
neutralize one milligramme of chlorine. The number of cc. of silver 
solution used gives the parts of chlorine per 100,000 of water; to express 
it in grains per English gallon multiply by 0.7. 
6. Determination of Phosphoric Acid in Phosphates.-The presence of 
phosphates is generally accepted as an indication of sewage contamina- 
tion, and their determination furnishes, therefore, strong corroborative 
evidence. In some cases they may be derived from the rocks through 
which the water has passed. A qualitative examination usually suffices, 
but to be more exact proceed as follows: 
The incinerated total residue of the solids is to be treated with a few 
drops of nitric acid, and the silica rendered insoluble by evaporation 
to dryness. The residue is then taken up with a few drops of dilute 
nitric acid; some water is added, and the solution is filtered, the filter 
having been washed with dilute nitric acid; 3 cc. of the filtrate is mixed 
with 3 cc. of molybdate of ammonia solution, gently warmed and set 
aside for fifteen minutes at a temperature of 80°. The result is reported 27 
as "traces," " heavy traces," or "very heavy traces." The precipitate 
may be collected and weighed, after washing with the least quantity of 
distilled water, and then dissolved to neutrality in dilute ammonia. The 
solution thus obtained is evaporated with repeated additions of small 
quantities of water, and the residue is weighed. The weight divided by 
28.6 indicates the amount of phosphoric anhydride; to express it in 
terms of PO4 divide by 21.4 (Parkes). 
' 7. Determination of Hardness.-The hardness of water may be due to 
salts of lime or magnesia, to volatile (C02) or fixed acid. To estimate 
the total hardness of water, place 70 cc. in a small stoppered bottle, 
and add the soap solution, shaking it strongly after each addition 
until a lather is formed which is permanent for five minutes. Then 
read off the number of cc. of the soap solution used. This solution 
is made of such a strength that 1 cc. is capable of exactly neutral- 
izing 1 milligramme of carbonate of lime. The number of cc. of 
soap solution required to form a lather in the 70 cc. of water is the 
number of milligrammes of carbonate of lime in the 70 cc., or the 
number of grains per gallon; we should, however, deduct 1 cc., as that 
amount is required to give a lather in 70 cc. of the purest, even distilled, 
waters. In Dr. Clark's scale, 1 grain of calcium carbonate or other salts 
per gallon is called 1 degree of hardness. The permanent or fixed hard- 
ness can be determined by the same process with water which has been 
boiled for half an hour and allowed to cool to 60°, and as the difference 
between the total and the permanent hardness is the temporary or 
removable hardness, the result of the permanent hardness should be 
deducted from the total hardness. The hardness due to magnesian salts 
can be estimated separately with the soap solution after precipitating 
all the lime salts with oxalate of ammonia. The amount of permanent 
hardness is important, as it chiefly depends upon calcium sulphate and 
chloride and the magnesian salts; it should scarcely exceed 3° or 4° of 
Clark's scale. It may be due to sewage contamination, as sewage is 
especially high in permanent hardness. 
8. Determination of Metals.-The addition of a drop of ammonium 
sulphide to some of the water in a porcelain dish will produce a dark 
coloration, even if only slight traces of iron, lead, or copper are present. 
If it is iron, the addition of a few drops of hydrochloric acid will cause 
the color to disappear, but the color remains if lead or copper is present. 
Whilst the presence of iron is of course harmless, water containing lead 
or copper should be rejected. In order to detect arsenic, large quanti- 
ties of the water must be distilled and the residue subjected to Marsh's 
test. 
The object of this examination is to determine the presence and char- 
acter of foreign matter, mineral, animal, or vegetable, found in the 
sediment or floating in the water, and to see in how far they may be con- 
nected with the water pollution from sewage or domestic refuse matter. 
Mineral particles are usually recognized by their crystalline or amor- 
phous character. 
Vegetable and animal matters, such as fibers of wool, cotton, linen, 
wood, starch cells, spiral threads of cabbage and other vegetables, 
macerated paper, human hairs, striped muscular fiber, and squamous 
IV. • Microscopical Examination of Water. 28 
epithelium, suggest the contamination of the water with sewage, possi- 
bly with human refuse. The remains of animals of all kinds, such as 
wings and legs of insects, spiders and their webs, particles of the skin of 
aquatic animals, are not uncommon. In addition to this we usually 
find living organisms of a low type, such as bacteria (micrococci, bacilli, 
and vibrionies), amoeba, and infusoria. Many of these may be perfectly 
harmless; others have been recognized as pathogenic, and all suggest 
the presence of organic matter, on which they feed. 
In water polluted with vegetable matters, we find fungi and molds, 
algse, diatoms, desmids, and various confervae. Among decaying vege- 
table matter will be found an abundance of micro-organisms, including 
bacteria, amoebae, different species of englenae, ciliated, free, and rapidly 
moving infusoria, such as kolpoda, paramaecia, coleps, stentor, kerona, 
stylonychia, etc. The presence of the anguillulae, or water worms, and 
rotifera, or wheel animalcules, is very common, and while of no special 
importance, they indicate a supply of organic food and, therefore, 
impurity of water. Then we have the entomostraca, such as the water 
flea, daphnia pulex, cyclops quadricornis, and others which occur in 
many good waters. The amphipoda, isopoda, and tardigrada (water 
bears) may be met, as well as the larvae of the water gnat, skip-jack, and 
the pupa form of many insects may be found in pond water. The 
presence of entozoa, their embryos and eggs, has already been referred 
to on page 20. The sewage fungus (Beggiatoa alba) is found in waters 
containing an excess of the sulphates, derived either directly from sew- 
age or from substances used in precipitating sewage or from waste water 
of manufactories. The fungus forms dense, flocculent, grayish-white 
masses attached to floating vegetation or to the banks of the stream. 
The microscope reveals an immense number of colorless threads contain- 
ing bright, strongly refractive, globular particles of sulphur; the threads 
branch dichotomously (Parkes). 
The foregoing list of microscopical objects is so large as to be confus- 
ing in attempts at identification and interpretation; it is well to remem- 
ber that the lowest forms of organisms, like bacteria, amoebae, fungi, ova, 
and ciliated infusoria, are strongly indicative of pollution and putre- 
factive changes. 
Cohn tells us that diatoms, green algae, and confervae predominate in 
water containing a small amount of organic matter, and that they are 
rarely found in decomposing water; in the latter the infusoria, par- 
ticularly the ciliated forms, the entromostraca, and wheel animalcules 
predominate. In waters rich in suspended organic matter, we find prin- 
cipally fungi, infusoria, carnivore, amoebae, anguillulae, and some wheel 
animalcules and tardigrada (water bears). In water containing a large 
amount of soluble organic matter, we find infusoria, flagellata, certain 
forms of amoebae, ciliated infusoria, and bacteria. 
Krapelin's studies of the fauna in the Hamburg water system are quite 
interesting. He found bryozoa, eels, snails, mussels, crabs, mollusks, 
worms, and all forms of the lowest animal organisms; also two species 
of marine animals: sea-crabs and platessa flessus. The air-breeding and 
vegetable-feeding animals were not found, but the aquatic animals sup- 
plied with gills, consumers of detritus, and aquatic animals of prey were 
largely represented. According to this author, the entire fauna in the 
water system is built up from the lowest forms of animal life, the higher 
species consuming the lower. 29 
V. Biological or Bacterioscopical Examination of the Water. 
The principal object of this examination is to determine the presence 
of pathogenic micro-parasites. The existence of harmless bacteria in 
water is of secondary importance, and is simply suggestive of danger, 
but not proof. We can infer from the number of bacteria found that the 
water is chemically good or bad, and in so far the counting of germs 
furnishes corroborative evidence of the presence of a larger or smaller 
amount of organic matter (ammonia, nitrates, or phosphates in the 
water, which constitute a suitable pabulum for these organisms). 
We have seen, however, that certain pathogenic bacteria have been 
found in water, and it is quite possible that disease germs do not retain 
their vitality for any length of time in different qualities of water; it i« 
also possible that they may be destroyed by other bacterial germs. In 
the bacteriological examination of water presumably contaminated with 
disease germs, it is therefore of the utmost importance that it shall pro- 
ceed without delay, and in taking samples it is also desirable to procure 
them from different depths and place them in sterilized flasks, properly 
secured. The examination may then proceed as follows: ''A measured 
quantity of the water-1 cc. or a fraction of 1 cc.-is mixed with a test- 
tube full of liquefied, sterilized, nutrient gelatine, a portion of which is 
then poured on a glass plate and placed under a bell jar, with suitable 
precautions to prevent the entrance of atmospheric spores. After a few 
days the germs or spores are found to have developed into recognizable 
colonies, which may be counted and differentiated by their color, their 
mode of growth, the liquefaction they produce in the gelatine, and other 
characteristics. Under the microscope, the colonies may be separated into 
the different varieties of bacteria, molds, and fungi, and each colony may 
subsequently be submitted to cultivation in test-tubes of gelatine, agar- 
agar, blood serum, etc." (Parkes). This last suggestion is especially 
important. If we find varieties of bacteria which are not common in 
water, and possibly of a pathogenic character, after obtaining pure cul- 
tivations through successive generations, they should be inoculated into 
animals, to determine whether they are reproduced.. For the simple 
recognition of bacteria it may suffice to put a few drops of the water 
on a clean glass slide placed on a piece of filtering paper under a bell 
jar. Let it evaporate, and draw the slide three times in succession 
through a gas flame; stain with a solution of gentian violet, and exam- 
ine by means of a high power microscope. The stained bacteria will 
thus be readily recognized. 
Purification of Water, 
Sufficient evidence has been adduced to indicate the necessity of free- 
ing the water supply as far as possible from foreign and contaminating 
ingredients, and this may, to a certain extent at least, be attained by 
the various methods recommended for the improvement of water. 
Boiling.-This is an old remedy for rendering hard water soft. It 
liberates the carbonic acid, and thus renders the lime and mineral mat- 
ters, except alkalies, which exist as carbonates, insoluble; the resulting 
deposit at the bottom also carries with it more or less organic impurity. 
Another important object of boiling, for at least thirty minutes, is the 30 
destruction of all the minute organisms, and which may include disease 
germs. Boiled water has lost its pungent, pleasant taste, and should be 
subjected to the rough aeration, which may be done by shaking, or pour- 
ing it back and forth through the air a few times. Hard water may 
also be softened by Clark's process, which consists in the addition of 
lime water, causing a precipitate of carbonate of lime. Nine ounces of 
quicklime will be sufficient for 400 gallons of water, provided the hard- 
ness does not exceed 30°. The addition of a little carbonate of soda 
(washing soda) will accomplish the same purpose. 
Distillation effects even a more complete purification of water than 
boiling. The first portions of the distillate containing generally volatile 
substances should of course be rejected. Distilled, like boiled, water 
tastes flat, and should be aerated, as suggested above, or by allowing 
the water to flow through sprinklers. Distillation of sea water is carried 
on on all ocean steamers. 
Freezing liberates the salts of sea water and destroys a large number 
of bacteria, but there is sufficient evidence to show that certain disease 
germs retain their vitality in ice for some time, and that freezing cannot 
be depended upon for the purification of water polluted with organic 
matter. 
Addition of Chemicals.-The addition of various chemicals to the 
water, for the purpose of hastening clarification by deposition, has been 
recommended by various authors. Of these the principal are: alum, 
perchloride of iron, sodium carbonate, and potassium permanganate. 
Hager recommends tannin for the destruction of algse, and Langfeldt 
extols citric acid for the same purpose. Whilst all these substances 
cause a precipitate, the same may be accomplished by allowing the water 
to settle; they have but little effect in purifying a foul water, or in 
destroying micro-organisms, and as none except the citric acid improve 
the taste of the water, we possess, in boiling, a far better remedy. 
Filtration.-The principal effect of filtration is the removal of the sus- 
pended matter in the water. In addition, however, filters, according 
to the material used, may eliminate some of the dissolved matters; this, 
of course, depends upon the size of the pores, the pressure, and abstract- 
ive qualities of the filter. The principal materials used in the con- 
struction of filters are: vegetable and animal charcoal, sand and other 
porous stones, wool, cotton wool, glass wool, felt, iron sponge, asbestos 
cloth, porous burned clay. 
Charcoal and bone-black, when properly prepared and fresh, certainly 
have the power of removing all of the suspended matter and a consider- 
able quantity of micro-organisms and dissolved matter, both mineral 
and organic. According to Knapp, vegetable charcoal removes 52.8 per 
cent of the total solids, 88 per cent of organic matter, and 23.8 per 
cent of the salts, whilst animal charcoal, when fresh, according to Uffel- 
mann, removes 67 per cent of the total solids, 89.2 per cent of organic 
matter, 24.1 per cent of the salts, and 80 per cent of the micro-parasites. 
The good effects, however, do not last longer than a few days. The 
eliminating power for microbes ceases very soon, and it becomes neces- 31 
sary to regenerate it by exposure to heat. If this is not done the filtered 
water may show more microbes than the original supply. 
Sand, especially sharp, angular, white sand grains not exceeding 1.5 
mm. in thickness, affords an excellent material for the elimination of 
suspended impurities. Sand also removes a certain amount of soluble 
organic matter, and assists in their oxidation. Uffelmann's experiments 
with a sand filter 1 meter deep show a removal of 38 per cent of oxi- 
dizable matter, 4.2 per cent of chlorine, 3.4 per cent of lime, 70 to 80 per 
cent of micro-parasites; in Hulna's experiments there was a removal of 
26.2 per cent of oxidizable matter, 33.6 per cent of ammonia, 50.2 per 
cent of albuminoid ammonia, 1.6 per cent of chlorine, 9.8 per cent of 
lime, 20.54 per cent of the total solids. 
Sand and gravel are used on a large scale in reservoirs for the purifi- 
cation of water. The water having first been received into settling 
reservoirs, where the bulky substances subside, is passed over the filter- 
beds, which consist of, first, layers of fine sand 2 to 3 feet deep, next a 
4-inch layer of coarse sand, next below a similar depth of small gravel, 
next a 6-inch layer of gravel the size of walnuts, and at the bottom a 
l-j-foot layer of cobblestones the size of apples. In the lower layer are 
the mouths of the outlet pipes, which convey the water to the pumping 
stations. Usually the depth of water on filter-beds is scarcely over two 
feet, and as the upper fine layer of sand catches most of the impurities, 
it is liable to become choked, and must be frequently removed and 
washed with the water jetted from a hose under high pressure. By 
means of such filters, Dr. Frankland tells us that 90 to 99 per cent of 
micro-organisms are removed from the London waterworks. 
Spongy iron, or porous metallic iron, obtained by roasting hematite 
iron ore, is used for the same purpose in London, Antwerp, and other 
cities. The fact that iron yields nothing injurious to water, and can be 
used for a considerable length of time without great deterioration, have 
been its strongest recommendation, but Pfarre found that the filtrated 
water is by no means free from micro-organisms, and the iron taste is, 
moreover, so objectionable that Antwerp subjects its water supply to an 
additional filtration through sand. 
Domestic Filters.-It has been truly said that they are probably more 
often a source of pollution of the water than otherwise, for the simple 
reason that no attention is paid to the removal and cleansing of the 
filtering material; in consequence, its pores become clogged with putres- 
cible organic matter, which favors the multiplication of bacteria, and it 
is not at all infrequent to find that the filtrate under such circumstances 
contains more bacteria than the unfiltered water. It should be under- 
stood that, in spite of advertisements, there is no such a thing as a " self- 
cleaning filter," and persons who neglect the cleaning had better do 
without filters altogether. They should be attended to at least once in 
ten days, and after thorough flushing with hose, the charcoal must be 
heated to redness under cover, in order to destroy the organic matter. 
From what has been said, no filter affords absolute freedom from microbes. 
This is not only true of the materials already referred to, but also of 
caferal (a mixture of iron, charcoal, and clay), wool, felt, and sponge. It 
is claimed, however, that glass wool, asbestos cloth, and %imglazed burned 
earthenware will remove all germs; there is no doubt that finely spun 
and pulverized glass wool, or asbestos pressed firmly into a cylinder, will 32 
accomplish this purpose for a time at least. " Breyer's microbe-mem- 
brane filter" is made on this principle, but Uffelmann's experiments 
have shown that whilst this filter is capable of entirely freeing of germs 
100 liters of water per day for six days, after that time the number of 
microbes in the filtrate increased from day to day. 
The " Pasteur-Chamberland filter" is made of five or six solid, porous, 
earthenware cylinders, surrounded with a metallic case, which is screwed 
on to the faucet, and the water is forced through the pores of the earthen- 
ware cylinders, and appears perfectly free from all suspended matter, and 
for a few days also free from bacteria and their spores. As it acts purely 
mechanically there is no alteration in the chemical composition of the 
water; but Uffelmann claims that even this filter loses its eliminating 
power for micro-organisms after five to six days' use. 
According to Parkes the essentials of a good filter are: 
(1) That every part of the filter shall be easily got at for the purpose 
of cleaning or renewing the medium. 
(2) That the medium have a sufficiently purifying power and be 
present in sufficient quantity. 
(3) That the medium yield to the water nothing that may favor the 
growth of low forms of life. 
(4) That the purifying power be reasonably lasting. 
(5) That in the construction of the filter itself there shall be nothing 
capable of undergoing putrefaction or of yielding metallic or other 
impurities to the water. 
(6) That the filtering material shall not be able to clog, and that the 
delivery of the water shall be reasonably rapid. 
We may add that the most important object of a filter is the elimina- 
tion of pathogenic bacteria, and, in order to do this effectually, filters 
must receive greater attention as regards cleansing and renewal than 
they have heretofore. It is perfectly evident that filters formed of loose 
particles, which give a more rapid delivery of water than finer materials, 
cannot be depended upon for the elimination of germs. Whilst the 
sand filters render the most effective service for the purification of water 
on a large scale, and the asbestos filter of Breyer and the Pasteur- 
Chamberland filter for domestic use, yet the English River Pollution 
Commission is doubtless correct in declaring that all the methods of puri- 
fication by filtration have so far been inadequate to prevent the propa- 
gation of epidemic diseases by water. We may also fully indorse their 
concluding opinion, that "nothing short of abandonment of the inex- 
pressibly nasty habit of mixing human excrement with our drinking 
water can confer upon us immunity from the propagation of epidemics 
through the medium of potable water." 
When we consider how very minute the specific bacteria really are, 
we need not wonder that they can readily pass through the filters of 
nature and the filters of man, without any effort of squeezing. In the 
epidemic of typhoid fever at Laussen, it was shown that specifically in- 
fected water had passed under ground for a half mile and contaminated 
a spring. In this instance the proof was made by a solution of chloride 
of sodium, and afterwards flour; the saline mixture found its way into 
the spring, but not the starch, all of which indicates that whilst filtra- 
tion prevented the passage of finely ground flour previously mixed with 
water, it was not capable of removing the specific germs of the disease. 
In our present state of knowledge, it would appear that nothing short 33 
of boiling or distillation can be relied upon to render polluted water 
harmless, and a good plan in the household is to boil the water first 
and then pass it through an aerating process; even simple agitation of 
boiled water will improve the taste, or in the absence of a more elaborate 
process, the air can be introduced by a bellows. 
Distribution of Water. 
In our discussion of rain water, springs, lakes, streams, rivers, and 
wells, we have dwelt with sufficient length upon the various sources of 
collection, and also disposed, so far as rain water is concerned, of the 
subject of storage in cisterns, tanks, etc. The question of storage and 
distribution in city waterworks needs our attention for a few minutes. 
The amount of storage required naturally depends upon the amount 
of water used and the facilities for replenishing it. We can readily 
calculate the space required when these conditions are obtained, namely: 
the number of gallons required daily for the whole population must be 
divided by 6.23 to bring into cubic feet, and multiplied by the number 
of days which the storage must last; the product is the necessary size of 
the reservoir in cubic feet (Parkes). Reservoirs are usually divided 
into receiving and distributing reservoirs. In the former, the water 
having been pumped in, or conducted from natural channels, is per- 
mitted to settle, depositing more or less of its suspended impurities; the 
water is then passed over the filter-beds to the high or distributing 
stations. It is needless to reiterate here that whatever the size of reser- 
voirs, they should be kept scrupulously clean and free from all sources 
of contamination; they should be covered, well ventilated, and rather 
deep, for the purpose of lessening evaporation and securing coolness. It 
is an open question whether, in the periodical cleaning of reservoirs, it 
is wise to disturb water-plants which grow in them, as some, like the 
protococcus and the clare, give out a certain amount of oxygen, and thus 
aid in the rapid oxidation of objectionable organic matter. Other plants, 
like the duckweed and some of the nostoc family, give rise to disagreeable 
odor and taste. In all cases of doubt it is best to remove some of the 
plants, place them in pure water, and determine whether they increase 
the amount of organic matter in water. When the houses are removed 
from sources of water, the supply should be conveyed in aqueducts and 
pipes; any other method is crude and objectionable. We have already 
referred to the colossal aqueducts of ancient Rome, and it may be well 
to mention that the modern city of Rome is to-day the best supplied 
city as regards water in the world. This has been accomplished by a 
thorough renovation of the ancient Agua Marcia, Agua Felice, Agua 
Vergine, and Agua Paola, which together supply not less than 3,000 
liters, or about 800 gallons, per head, daily. 
The public in towns and cities of this country is now very generally 
supplied by well-regulated water companies. The supply for villages, 
isolated houses, and farms has been discussed in connection with wells, 
springs, etc. 
The water from public works in the United States is distributed from 
the reservoirs by means of iron pipes. As iron pipes are liable to rust, 
and to clog from accumulated rust, not to mention the absolute corro- 
sion, the interior of the pipes should be coated with hot pitch, tar, or 
vitreous glass. The magnetic oxide of iron produced on the surface of 
3k 34 
the metal by " Barff's process " is also employed. The practice of calk- 
ing the joints with tow or gaskin next the interior of the pipe, and then 
running the joint with molten lead, is no longer tolerated; the pipes are 
screwed together, and in the case of mains large enough for a man to 
enter, the inside of the joint should be pointed with Portland cement. 
The amount of leakage is great enough, without carelessness. Leak- 
age often takes place from uneven settling of the ground after laying the 
pipes, or from the vibration of heavy traffic, causing fracture of the 
pipes and joints. Parkes tells us that in London fifteen gallons out of 
the thirty-five supplied per head daily thus run to waste in the soil. 
The amount of waste is, of course, greatly influenced by the pressure. 
For the purpose of detecting such leakages, meters have been designed, 
which are placed on each district main; they register the flow by day 
and night, and as very little water is consumed during the night season, 
it can be safely concluded that the amount registered, or at least the 
greater portion of it, is running to waste. The exact spots where the 
leakages are taking place can be determined by the vibrations produced 
thereby in the nearest house-communication pipes, which can be dis- 
tinctly heard by applying the ear to the pipe, and frequently without 
doing so. 
The house-communication pipes are generally of lead. Hygiene can- 
not approve of their employment, for they are liable to be acted upon, 
especially by soft water, and in consequence there may be danger of lead 
poisoning to the consumer. On the other hand, it is claimed that hard 
waters containing salts of lime and magnesia, either have very little 
solvent action on lead, or they quickly coat the metal with sulphate or 
basic carbonate of lead, which prevents further action. Odling sug- 
gests that whilst new lead pipes are acted on by soft waters, forming a 
soluble oxide of lead, this ceases after awhile, owing to a coating of car- 
bonate of lead, the only exception being waters which are quite free from 
silica or its compounds. In the water supply of Glasgow, from Loch 
Katrine, it would appear that there is a deposit of peaty or vegetable 
matter, which prevents all further action of the water upon the metal, 
though the original water acts most powerfully upon lead. 
Other observers claim that the soft, highly oxygenated waters, and 
those containing organic matters, nitrites, nitrates, and chlorides, are 
those which have the most solvent action on lead. In our present state 
of knowledge, it is simply fair to state that hard waters have little or no 
solvent action on lead, whilst soft waters are liable to do so, especially 
soft oxygenated waters derived from an intermittent service. We are 
not prepared to deny or admit that the action of soft water ceases on lead 
after a few weeks, or whether free carbonic acid favors plumbo-solvent 
action or not, neither can we explain at present the role which nitrates 
and chlorides play in this matter. The Sixth International Congress 
for Hygiene condemned the use of leaden pipes, and also imperfectly- 
tinned leaden pipes. Where lead poisoning is feared, a block-tin pipe 
should be substituted for the lead pipe, and if this is not done, the water 
in the house pipes should be run to waste every morning. 
The supply of water to houses has been conducted on two systems, the 
intermittent and the constant service; which simply means that in the 
former the flow of water in the mains is stopped, except for a few hours 
every day, requiring, therefore, provisions for the storage of water on the 
premises of the consumer, whilst in the constant service, the mains being 35 
always turned on, no storage facilities are required, except small tanks 
for the flushing of water-closets. When we remember the various causes 
liable to contaminate the water stored in cisterns, tanks, barrels, buckets, 
etc., it needs no argument to condemn the intermittent supply. Even 
if it could be tolerated in well-regulated houses, think of this service in 
the homes of the poor, the tenement houses of great cities, where the 
water is often stored in the most filthy receptacles. Fortunately for 
Americans, we have a better water service than England and some con- 
tinental countries. The constant service is being rapidly introduced 
into English towns; over one hundred and fifty towns and the greater 
part of East London are now provided with a constant service, and the 
results have been especially beneficial to the poorer classes. Such a 
service, to be of real merit, must of course deliver sufficient water at all 
times, and not merely delude us with the name. 
All the leaden service pipes of a house should be strong (12 pounds 
per yard for 1-inch pipes and 6 pounds per yard for pipes) in 
order to withstand the constant pressure. If this pressure is maintained 
in the mains by pumping, and not by high level reservoirs, greater 
power must be used in the morning, as the greatest quantity is consumed 
at that time. 
In this connection it is well to refer to the fact that when water mains 
and sewers are laid in the same trench, there is a possibility of foul 
matters which have escaped from leaky sewers being sucked into the 
water mains during intermissions in the service. The remedy is obvious: 
the water and sewage systems should be kept apart as far as possible. 
Ice and Artificial Carbonated Waters. 
Before dismissing this subject, it is proper to refer to the matter of ice, 
which plays such an important role in American households. The 
" pernicious ice-water pitcher " of Dr. Hammond is not only objection- 
able because of the bad effect of a low temperature on our digestive 
organs, but also because of the impurities likely to be contained in the 
ice. I have seen, time and time again, persons of intelligence use noth- 
ing but melted ice, with the firm belief that they were taking the purest 
of water, forgetting entirely that whilst some of the organisms are 
destroyed, others retain their vitality, and that, broadly speaking, freez- 
ing does not eliminate the organic impurities. The fact is that ice 
obtained from " a pond or river which is unfit as a water supply, is 
equally unfit for use." Ice water should contain no perceptible suspended 
matter, very little dissolved matter or chlorine, and the albuminoid 
ammonia should not exceed 0.005 part per 100,000. 
The number of micro-organisms found in ice depends first upon the 
purity of the original water, and secondly upon the length of time the 
ice has been kept. This has been demonstrated by various investigators. 
Nerger found that 1 cc. of river ice, frozen January 4, 1887, contained 
440 germs. He examined 3 days later and found 273 germs per 1 cc.; 
after 6 days, 180 germs per 1 cc.; after 9 days, 40 germs per 1 cc.; after 
13 days, 6 germs per 1 cc.; after 15 days, 2 germs per 1 cc.; after 20 
days, 4 germs per 1 cc. Prudden's interesting experiments (Med. Rec- 
ord, March 26, 1887) show that 1 cc. of water contained 6,300 germs of 
the Micrococcus prodigiosus. He subjected this water to freezing, and 
found that the ice contained after 4 days, 2,970 germs; after 37 days, 22 36 
germs; after 51 days, 0 germs. The results with water containing the 
germs of Proteus vulgaris, and another sample containing the bacilli of 
typhoid, were even more striking. All of which emphatically indicates 
that the presence of bacteria in ice depends largely upon the length of 
time the ice has been frozen. There can be no question as to the com- 
parative purity of artificial ice manufactured from distilled water, in 
which Frankel only found from 0 to 14 germs, and Uffelmann from 0 to 
22 per 1 cc. 
Now, whilst it is true that so far no pathogenic bacteria have been 
found in ice, their presence is at least possible if contained in the water 
previous to its freezing. Prudden kept the ice frozen from water con- 
taining typhoid bacilli for 103 days, and at the expiration still found 
7,300 per 1 cc. Nerger has shown that the bacilli of anthrax retain 
their vitality in ice for 14 days, and Friedlander's pneumonia cocci 
about a week. These observations are certainly suggestive of danger 
from impure ice, and for this reason preference should be given to arti- 
ficial ice made from distilled water. In this connection I may relate an 
amusing incident of my frontier life. Last summer I visited almost 
every evening the family of a professional friend. About 9 o'clock regu- 
larly the punch or lemonade bowl appeared. I invariably declined the 
tempting beverage because the ice supply was obtained from a polluted 
ice pond. After the refreshments each of the three adults, my good 
friend the doctor included, would take one or two five-grain capsules of 
quinine, as they " all had symptoms of malaria." I finally suggested 
that the organic impurities contained in the ice might possibly produce 
the symptoms complained of, and they contented themselves thereafter 
with cooling the beverages by setting them on the ice. The symptoms 
of malaria soon disappeared. 
Carbonated Water.-We have already seen that water rich in carbon 
dioxide is especially pleasant to the taste, and exerts a good effect on 
the digestive functions. These waters are either natural or artificial, 
and as they are largely consumed for medicinal and dietetic purposes, 
it is proper to present here the results of studies made in reference to the 
amount of carbon dioxide, and the number of micro-organisms con- 
tained in such wTaters. The natural carbonated waters contain between 
200 and 2,000 cc. of free CO2 per liter. No examination has been made 
to determine the number of germs in natural carbonated water, but 
Leone found in freshly prepared artificial water, 186 germs per 1 cc.; 
after 5 days, only 87 germs; after 10 days, 30 germs; after 15 days, 20 
germs. This author attributes the disappearance entirely to the fatal 
effects of CO2 on the microbes. Sohnke observed a similar diminution, 
especially when the bottles were supplied with patent stoppers, whilst 
ordinary corks afforded no such results. Hochstetter, quoted by Uffel- 
mann, howevei* found that samples of artificial seltzer water contained 
from 10 to 75,000 germs per 1 cc. when taken from bottles with patent 
stoppers, and even more when taken from bottles with common corks. 
He also found that the number of micro-organisms increased rather 
than diminished by keeping. In his experiments, conducted in the 
Imperial Health Office at Berlin, he demonstrated that the bacilli of 
septicaemia, cholera, and anthrax survived in this water but a few 
hours, whilst the bacilli of typhoid retained their vitality for days and 37 
weeks, and the spores of the bacilli of anthrax showed no loss of vitality- 
after several months. 
Hellwig reports an outbreak of enteric fever in 1884, in the city of 
Mayence, Germany, which affected only persons who had been drinking 
artificial seltzer water from a certain establishment. Investigation 
revealed the fact that the water used was taken from a well notoriously 
impure and polluted with sewage from a cesspool which had received 
the evacuations of a typhoid patient. Whilst there was no bacterio- 
logical proof that the water contained the bacilli, it is highly probable 
that the germs of typhoid were transmitted in the artificial mineral 
water prepared from this infected source. 
For this and the additional reason, that carbonic acid naturally favors 
putrefaction'of organic matter, it is certainly high time that these arti- 
ficial carbonated waters should be prepared from distilled water.