[Extracted from the American Jour, of Science and Arts, 2nd Series, Vol. XIX, 1855.] 
On a remarkable change which has taken place in the compo- 
sition and characters of the Water, supplied loathe City of 
Boston, from Lake Cochituate; by Augustus A. Hayes, M.D., 
Assayer to State of Massachusetts. 
(Read at a meeting of the American Academy, 11th January, 1855.) 
Ix the study of the chemical composition of waters, used for 
domestic, purposes, a wide field is opened for inquiries of high 
scientific interest, as the accurate comparisons of different waters, 
lead us through both departments of modern chemistry, the or- 
ganic and inorganic. This interest is however secondary to the 
importance of careful inquiries in an economical view, as we 
have actions of waters on substances with which they come 
in contact, at one point modifying their composition so as to 
render them purer or less salubrious, and when a water passes 
some distance, its characters may thus be made to differ at dif- 
ferent points. Not only is the water changed by contact with 
different bodies, with which it is brought in contact, but conduits 
of masonry or iron are in special cases rapidly destroyed. 
Although my observations on the water supplied to this city 
were among the earliest made before its introduction, they have 
been continued since that time, and within two years partial 
analyses have been made almost weekly, for the purpose of learn- 
ing the cause of any changes occurring. The results thus ob- 
tained will be given in a future paper, with the conclusions ar- 
rived at, in a general form-while at present, it is my design to 
call attention to the condition of the water, as it has existed for 
about ten weeks. 
Cochituate water, derived mostly from surface drainage, as it 
is found in the Pond or Lake, belongs to the class of peaty wa- 
ters, so common in New England. It has not characters in com- 
mon with the green or colorless waters of limestone formations, 
nor the medium or mixed qualities of our river waters. In its 
normal state, it may be considered as a pure water, holding in so- 
lution four or five grains of mineral salts in one U. S. standard 
gallon, and these consist of compounds of chlorine with sodium, 
potassium, calcium, and magnesium, carbonates and silicates of 
these bases, in varying proportions at different seasons. Its or- 
ganic constituents, including the gases dissolved, are those of the 
most importance, as they give it particular characters, modifying 
its chemical relations and affecting the taste, color, and purity of 
the fluid. 
In the spring and autumnal seasons, there are found ulmic, 
crenic and apocrenic, and humic acids, with sparingly soluble com- 
pounds of these acids and bases, including alumina and oxyd of 
Second Series, Vol. XIX, No. 56.-March, 1855. 2 
A. A. Hayes on the Cochituate Water. 
iron. With them there is a neutral body, which resembles mucil- 
age from gum, and is usually in a changing state, especially while 
the water is warm, in the summer season. The gases dissolved are 
oxygen, nitrogen, and carbonic acid : the nitrogen never has the 
volume relation to the oxygen which exists in the air, being, ex- 
cept in rare instances, in smaller proportion, and cases have oc- 
curred, when the nitrogen was no more than 20 volumes to the 
oxygen 80. The volume of carbonic acid also varies, while about 
one volume of all the gases exists in thirty-six of normal water. 
There are present, also numerous animalcules and infusoria, fresh- 
water sponges and abundance of ochry matter, resulting from the 
chemical action of the water on the iron pipes. The animalcules 
indicate a state, which really exists,-of a disturbed balance be- 
tween the fish, crustaceans, animalcules, and sub-aqueous vegeta- 
tion of the lake. Although throughout the year, the water, at 
times increased by rains and melting snow, cannot be classed with 
putrid waters, there are periods in every season, during which it 
closely approaches to these in character. 
In the latter part of October last, I was watching, for the in- 
creased amount of organic acids, due to the decomposition of 
vegetable matter, after a season of drought, succeeded by copious 
rains, when I was greatly surprised to find the humates and apo- 
crenates giving place to crenic acid and crenates, accompanied by 
a perceptible odor of decomposing vegeto-animal matter, such as 
is emitted by freshly disturbed soil. This odor, which character- 
izes the humus from animal matter, continued several days, the 
water became colorless, while the organic matter, including car- 
bonic acid, increased so as to exceed nineteen times the minimum 
amount previously found. The condensed vapor from the water 
had a strong odor of earth, or precisely that of guano from humid 
climates, and possessed an acrid reaction. No more than a mere 
trace of ammonia could be thus detected. When the water was 
mixed with lime and distilled, the condensed vapor was ammo- 
niacal, proving that no carbonate of ammonia from the soil was 
present, but a salt of ammonia due to decomposition. The 
earthy odor, or (so called) taste, was succeeded by one closely 
resembling that of fresh-water fish, which, with slight variations 
in intensity, has continued nearly ten weeks. Before the water 
throughout the city became thus contaminated, the suggestion 
arose that the cause was local; the secondary main supplying my 
dwelling-house having perhaps retained some parts of eels or fish. 
A careful examination was made and by analysis, a portion of oil 
was separated from the water, which had been filtered through 
muslin to remove suspended impurities. 
By distillation, the odor could be isolated from the water, which 
thus lost, what was pronounced by good judges, to be the taste of 
fish oil, while the water, retained the oil, almost destitute of odor. A. A. Hayes on the Cochituate Water. 
3 
The general supply of water to a populous city, had thus be- 
come very offensive, without any adequate cause appearing, and 
the evil led to the expression of many hypotheses and supposi- 
tions, chiefly without reliable support. 
As the subject was one within the reach of experiment, the 
course adopted was the following: A displacement apparatus of 
glass, was charged with recently calcined animal charcoal, of me- 
dium fineness; over this was placed a conical filter of clean cotton, 
so that any water, falling on the charcoal, would first pass through 
the cotton filter. The water from a contracted supply pipe, was 
allowed to flow slowly on the cotton filter, and passed away, so 
long as the pores remained open. Removing the cotton filter, 
the charcoal was allowed to drain, the water displaced by alcohol, 
and the alcohol by sulphuric ether, without removing the coal. 
Some oil was found in the alcoholic fluid, while the aqueous 
ether was colored by it, from a tint of yellow to a light olive 
color. 
By evaporation at 90° to 100°, the ether left some globules of 
fluid oil, but by far the larger bulk of residue, was a soft solid in 
granules, without crystalline form. By warming the solid with a 
little acid, a base was dissolved, generally lime, or lime and ammo- 
nia, while the oil floated on the fluid, and was left by evaporation 
of the water. As thus obtained, this oil was of a light yellow 
color, presenting both oleic and stearic acids. Its specific gravity 
was the same as that of lard oil. Alcohol dissolved it without resi- 
due. A solution of carbonate of soda saponified it when warmed, 
proving the acid condition of the oil. With sulphuric acid it 
blackened, and chlorine changed its color to dark brown. 
The oil, as separated from the etherial solution, in different ex- 
periments, assumed a solid state at 80° or 90° F. Acids elimin- 
ated oily fluids constantly, with the emission of a peculiar odor. 
Treated with carbonate of soda, when the soap was decomposed, 
an odor resembling that from adipocere was generally percepti- 
ble. When the charcoal, while wet from the water, was distil- 
led, the vapor, which was first condensed, had a strong fish-1 ike 
odor. It would putrefy and run through the changes resulting 
from the production of Conferva. 
The mass of the water supply, was constantly changing from its 
state of approach to putrefactive fermentation-in which free cre- 
nicacidand crenates appeared, witha large volume of carbonic acid 
-to its more nearly normal state. At one time, twenty-eight vol- 
umes of water evolved, by boiling, one volume of gases. Twen- 
ty-five volumes of the gases were diminished only one volume, by 
phosphorus, warmed and left twenty-four hours ; or about four 
per cent, of oxygen, seventy of carbonic acid, and twenty-six of 
nitrogen. Such a gaseous atmosphere dissolved in water, could 
not support animal life, in the higher forms of organization. As 
the oxygen gas increased in volume, the apocrenates and humates 4 
A. A. Hayes on the Cochituate Water. 
appeared, and the water which had no action on iron, assumed 
its ordinary action on this metal. The'crustaceans increased in 
quantity and size, the Cyclopsand Daphnia became predominant, 
and the cotton filters were soon closed by their bodies. Atten- 
tion was now given to the mass collected on the filter, as had al- 
ready been done with the sponges, and some vegetable organ- 
isms, including Conferva. 
The fish-like odor was mostly retained by the filter, which 
had not been the case in the earlier experiments, and it became 
easy to separate from the gelatinous mass on the cotton, the oil, 
with the odor, or apart from it. As separated from the mass, the 
oil possessed a fugitive green color, at times, but the dried filters 
extracted by ether, afforded a yellow oil. The variations in 
color were found to be due to the state of the matter on the 
filter, which, evidently of animal origin, decayed rapidly, and the 
oil and odor became merged in a body, much like adipocere. 
The water, which had been purified by means of animal char- 
coal, was free from taste and odor; its vapor did not possess odor, 
and the larger part of the organic matter had disappeared. 
As the chief contaminating matter in this water was arrested 
from a current by even a coarse filter, and the experiments had 
been repeated so frequently as to leave little else for chemical 
trials, 1 placed in the hands of Dr. John Bacon, for microscopical 
examination, the substance, like that, from which the odorous oil 
had been taken. 
Dr. Bacon at once detected the source of the oil, the bodies of 
the Cyclops and Daphnia, being in large part filled with it,*-ten 
or fifteen globules, of different sizes, could be seen in a single 
subject,-but the most remarkable fact in this connection is the 
varied color of the oil. Under the microscope while many sub- 
jects presented a yellowish-brown oil, some were filled with col- 
orless oil, and not a few had oil of a blackish blue, shading to in- 
digo blue. 
This fact explains the production of green and olive green 
etherial solutions, and it was found that the decomposing re- 
mains, were often red and yellowish brown-and in that case af- 
forded light yellow solutions. No other substance, but those 
named, was found among numerous collections, which could af- 
ford oil; the connection between the chemical proofs, and mi- 
croscopical observations was most skillfully made by Dr. Bacon, 
in the way of extracting the oil, while the subject was in the 
field of the instrument. 
At this point of the research, a series of experiments was un- 
dertaken, which demonstrated that the fluid oil first obtained by 
animal charcoal, was really due to the presence of broken up and 
dead crustaceans, which had given free oil to the water. 
* The species of Cyclops and Daphnia are usually between £th and of an 
inch in length. « J. Bacon on Oil in Crustaceans found in Cochituate Water. 
5 
Certain modifications of the oil which had been observed, 
could be traced to the slate of the mass of crustaceans, before the 
ether was used as collected at the present time from a portion of 
water by means of filters of different degrees of fineness, from 
coarse to very fine, we have the water on one hand free from 
taste, while the fillers retain the matter which rendered the water 
impure. /I portion of this matter placed in pure water gives to 
it the taste of Cochituate water, while another poriion under the 
microscope presents only living and dead crustaceans. 
Dr. Bacon has kindly recorded his observations and allowed 
me to append his account of them to this paper. 
Observations on the Oil contained in the Crustaceans found in 
the Cochituate Waler, by John Bacon, M.D. 
The occurrence of numerous transparent globules in the bodies 
of the minute crustaceans found in the Cochituate water, first 
attracted my notice in the spring of 1854, and I then ascer- 
tained by chemical tests that they consisted of oil. Supposing 
that they were ova in some stage of development and were 
probably well known to naturalists, no further observations were 
made until the bad condition of the Cochituate water attracted 
public attention ; when I called the attention of one of the chem- 
ists employed to analyze the water to the presence of this oil 
and suggested that it might be the cause of the evil. But it 
did not appear probable to either of us that a small amount of oil 
could occasion so serious an effect: and thus the matter rested 
until the commencement of the present year, when Dr. Hayes 
placed in my hands for microscopical examination the gelatinous 
substance collected by him on cloth filters. The microscope re- 
vealed an abundance of oily globules, .in the bodies of the Cy- 
clops and other minute crustaceans, of which the mass on the 
filter chiefly consisted, and the source of the oil obtained in his 
experiments was at once evident. At this time, early in January, 
very few Conferva and other vegetable organisms were found. 
The empty silicious shells of various Diatomaceae were abundant 
as usual, but scarcely any specimens were living, or contained 
organic matter. Yet the peculiar flavor of the water was as 
strongly marked, as in the autumn, when Conferva and other veg- 
etable organisms abounded. The crustaceans in which the oil 
occurs are several species or varieties of Cyclops and Daphnia, and 
probably other allied genera of the division Entomostraca. In the 
living animals, the oil is clearly seen by the aid of the microscope, 
through the carapace which is mostly transparent; and it is dis- 
tinguished by its high refractive power and other optical charac- 
ters from the other contents of the shell. It can also be extracted 
by ether, and still more satisfactorily, by strong alcohol from the 
body of the animal, while in the field of the microscope. The 6 
J. Bacon on Oil in Crustaceans found in Cochituate Water. 
quantity present is exceedingly variable, not only at different times, 
but in different individuals collected at the same time. In a few 
specimens no globules are visible. In others they are so abund- 
ant, that the oil forms at least one quarter part of the bulk of the 
animal. These large quantities occur only in the Cyclops, which 
is by far the most abundant form present; the other crustaceans 
contain much less. 
Ils distribution in the body of the animal is remarkable, being 
diffused irregularly in globules of various sizes, (usually spherical 
and occasionally ovoid or pear-shaped,) and in masses formed by 
the coalescence of globules; and it appears to have no definite 
connection with the internal organs of the animal. Sometimes, 
small globules are seen even in the last joints of the tail. No sac 
or envelop is visible around them, as they occur in the animal, or 
when liberated by tearing the body into fragments. Yet glob- 
ules lying in contact in the body do not unite by moderate pres- 
sure, but regain their form when the pressure is removed. 
A strong pressure causes them to run together. These facts 
are compatible with the absence of a proper enveloping mem- 
brane. No structure of any kind is visible in the globules. 
Their color, when isolated, is generally orange, red, or yellow ; 
they range, however, from brownish red to an entirely colorless 
condition, in different specimens. As the carapace has frequently 
a tinge of red or green, the color of the oil is of course affected 
when seen through it. 
Finding that the comparatively large size of the crustaceans, 
allowed of their almost perfect separation from the other bodies 
suspended in the water, by means of a suitable filter, a quantity was 
collected from a Cochituate service pipe, and thoroughly washed 
with distilled water. They were then introduced, mostly in a 
living state, into distilled water, in an open vessel. In about half 
an hour, the water began to acquire an odor, and after some 
hours, both the odor and taste resembled closely the peculiar 
flavor of the Cochituate. In a day or two, a decided fishy flavor 
was developed. The water was now somewhat milky, and on 
microscopic examination, an abundance of colorless oil globules, 
were seen diffused through it, with some gelatinous matter, de- 
rived from the bodies of the dead crustaceans, with the fragments 
of which, together with exuviae, the bottom of the vessel was 
covered. A large proportion were still living and active. In 
about a week, the water began to regain its clearness, and the 
odor and taste nearly disappeared. Many of the crustaceans were 
still alive ; and it was noticed that a progressive diminution in the 
general amount of oil contained in their bodies, was evident in 
the successive examinations. 
In the Cyclops, these globules are found equally in both sexes, 
and cannot therefore be derived from the ova; in many of the J. Bacon on Oil in Crustaceans foztnd in Cochituate Water. 
7 
females, the granular ova masses, in the internal ovaries, are seen 
in company with the globules-but they are not in connection, 
nor is there any indication of a transition from one form to the 
other. 
In the Daphnia, the small pellucid globules which constitute the 
earliest stage of the ova, and also the hibernating eggs, are visi- 
ble in many specimens, and do not resemble the globules under 
consideration. The male Daphnia is rarely seen, and I do not 
know whether the oil is found in both sexes as in the Cyclops. 
Since the above observations were made, I have learned, that 
these oil globules are briefly described by von Siebold. See Dr. 
Burnett's translation of von Siebold's Anatomy of the Inverte- 
brata, pp. 310 and 334. This author regards them as fat cells, 
and after stating that they occur in many crustaceans, adds the 
following remarks: "The fat, which these cells contain plays a 
part, probably, in digestion and assimilation ; for with these ani- 
mals, the excess of nutriment is deposited as fat to be used in 
times of need, as for example, during the act of moulting. This 
explains why the quantity found is so variable, or even may be 
entirely wanting." I cannot find that they are described by other 
authors, nor are the appearances, which they present in the crus- 
taceans of the Cochituate, represented in any of the figures I have 
seen.