With the Compliments of Wm. Ripley Nichols. 
HEPOET S 
OF - ’ 
/ 
Professor Nichols and Dr. Far low 
ON MATTERS CONNECTED WITH THE 
BOSTON WATER SUPPLY. 
[From the Report of the Water Board, 1877.] 
BOSTON: 
PRESS OF ROCKWELL AND CHURCHILL, 
NO. 39 ARCH STREET. 
1877. REPORTS ON CONDITION OF HORN POND 
REPORT OF PROFESSOR NICIIOLS. 
To the Water Commissioners of the City of Boston: — 
Gentlemen, — On the 8th inst. I was requested by you to visit Horn 
pond, one of the ponds connecting with the Mystic-water supply, in 
order to investigate the present condition of the water. In accordance 
with your request I visited the locality on the following day, and made 
the entire circuit of the pond in a boat. 
I found the trouble to be due to the presence in the water of an 
enormous number of a microscopic organism, an alga belonging to 
Nostoc family, subsequently identified by Dr. Farlow as an Anabcma 
(perhaps gigantea). 
The water over the whole surface of the pond, and to the depth of 
several inches, was filled with these minute bodies, which gave to it a 
greenish-yellow hue. The same vegetable matter in other stages of 
growth and decay had caused the accumulation of large masses of 
variously colored gelatinous matter, and where it was in a state of decay 
the odor was very disagreeable, reminding one of a pig-pen more than 
of anything else. 
Most ponds and reservoirs are liable in summer to be troubled by 
such growths, and it is probable that each year there has been more or 
less in Horn pond; but never, as far as I can learn, has the trouble been 
so great. The water supplies of other cities have, however, been 
affected in the same way, and in the report of the Water Hoard of New 
York for 1859, and in that of Albany for 1865, may be found a descrip- 
tion of a similar condition of things. 
Under the circumstances I did not judge that any chemical examination 
would be necessary, but in order to identify fully the vegetable growth, 
and especially in order to learn if there was anything in the condition 
and surroundings of the pond which might tend to cause or to aggravate 
the evil, I requested Dr. Farlow, Professor of Botany in Harvard 
University, to examine the pond, and to identify such vegetable species 
as might have a bearing on this subject. I visited the pond, in company 
with Dr. Farlow, on the 12th inst. At that time the condition of things 3 
was much improved, and the water was becoming clearer; in Wedge 
pond, however, the water was rather worse than in Horn pond. Dr. 
Farlow’s statement accompanies this report. 
The two practical questions which arise are,.whether the matter is 
injurious to health, and whether anything can be done to prevent the 
reoccurrence of the trouble. I do not know of any direct evidence as 
to the wholesomeness or unwholesomeness of the water when in this 
condition. 
The vegetable matter is not generally considered injurious, but it 
gives to the water, especially when decaying, a disagreeable taste and 
odor, much of which can be removed by filtration; most efficiently by 
means of filters of animal charcoal, which should be frequently cleansed. 
It would be, with our present knowledge, impossible in any way to 
prevent the growth of the plant in the pond ; but it is the opinion of Dr. 
Farlow that the abundance of the growth may be in a measure due to 
the presence in the upper part of the pond of large masses of another 
plant, a species of Plectonema. This plant may perhaps be described as 
resembling masses of tangled horse-hair as much as anything, except 
that when held up, so that the light shines through, it is evidently bluish- 
green. This plant begins to grow on sticks and stalks of other plants 
under water, most commonly at a depth of not more than ten or fifteen 
feet, but subsequently rises in large masses to the surface, and furnishes 
a favorable starting point for the growth of the Anabcena. I do not 
know whether there is more this year than usual; there is certainly a 
large quantity of it. Whether it would be of any use to remove this 
now, it would be impossible to say, but it would be well another year, 
between the middle and last of June, to remove as much of it as 
practicable. 
1 would further suggest the desirability of some sort of screen at the 
outlet of Horn pond, by which the masses of floating material might 
be arrested. The present year it would have been possible to remove 
at this point, and also along the shores of the pond, much of the decom- 
posing matter which, after a time, found its way to the lower pond. 
Yours respectfully, 
WM. ItlFLEY NICHOLS. 
Mass. Institute of Technology, 
Boston, Aug. 1G, 1876. REPORT OF DR. FARLOW. 
To the Board of Water Commissioners of the City of Boston :— 
Gentlemen, — By request of Prof. W. It. Nichols I went with him to 
Horn pond, in the middle of the month of August, for the purpose of 
ascertaining if it were possible to account for the disagreeable odor 
exhaled by the water, owing to the presence of any vegetable substance 
visible to the naked eye or determinable by the microscope. We walked 
for some distance along the shore of the pond, and examined the water 
at both the upper and lower ends. 1 took away with me, for micro- 
scopical analysis, some bottles of the water, and others were sent me by 
Prof. Nichols. 
The odor seemed to be caused by the presence in the water of a large 
mass of a species of Anabocna in a state of decomposition. This was 
perceptible to the naked eye, floating in the water in a healthy con- 
dition in the form of minute glistening rods, and also collected on the 
surface, and often adhering to sticks and plants in gelatinous masses, at 
first of a bluish-green, and afterwards of a brown color, in which con- 
dition it was more or less decomposed, and emitted an odor which re- 
minded one of horse-dung. 
A microscopic examination showed a large number of filaments 
which could be recognized as belonging to a species of Anabama, but, 
unfortunately, so far decayed as to render the determination of the 
species impossible. Although to be regretted in a scientific point of 
view that the specific name could not be determined, as far as all prac- 
tical bearings of the case are concerned it is of no consequence. The 
genus Anabama belongs to the order Nostochinece, the order to which 
belong most of the plants which appear suddenly in fresh or salt water, 
often accompanied by a disagreeable odor. As an example, I may 
mention the plant Trichodesmium roseum, to which the Red Sea owes its 
color, which appears suddenly in immense masses and as suddenly dis- 
appears. 
To anticipate the appearance of the Anabama, and to prevent its 
growth, is at least, in the present state of knowledge, impossible. That 
is not, however, necessary in the present case, for so long as the Ana- 
bama floats freely in the water it is not likely to prove offensive. 
When, however, it collects in masses on the surface, exposed to the heat 
of a midsummer’s sun, it at once begins to decompose. This collecting 
on the surface is favored when the water of the pond is low enough to 5 
allow the weeds growing in it to reach the surface; for the Anabcena 
collects readily on water weeds and sticks. There is furthermore in 
Horn pond an alga, which is very abundant, and which must have a 
great deal to do with hastening the decay of the Anabcena. About a 
year ago I received from a gentleman in Bethlehem, Pa., a curious 
alga, not only new to this country, but to the world, which I named after 
the discoverer, Plectonema Wollei, and which I had intended to describe 
in a paper to be published in a few weeks. This plant, which I saw 
growing for the first time in Horn pond, forms long matted tufts of a 
spongy consistence, formed of an immense number of long, dark green 
threads closely interlaced. It is attached in the beginning to sticks 
and water plants, and grows in length until it reaches the surface of 
the water. Later in the season it breaks away from its attachment, 
floats round on or near the surface in patches of greater or less extent, 
and is finally washed ashore. I visited the pond on October 3d, and 
found that the large attached masses which Prof. Nichols and myself 
had observed in August at the upper end of the pond, had disappeared, 
and that large quantities had been washed up on the beach. 
The Plectonema Wollei, from its spongy nature and filamentous struc- 
ture, must absorb into its meshes and collect on its surface quantities of 
the Anabcena, which, thus forcibly retained on the surface and exposed 
to the sun’s rays, must soon decompose. 
It seems as though it might be desirable as a preventive measure to 
remove the Plectonema. It probably does not reach any perceptible 
size before the middle of June, and from that time until July would be 
the most favorable period for removing it. If the pond is kept com- 
paratively clear of the Plectonema one great source of danger from the 
Anabcena is avoided. 
Respectfully submitted, 
(Signed) W. G. FARLOW. 
Boston, October 5, 1876. 
The Plectonema which I have mentioned is known to persons living 
near the pond under the name of “ eel grass.” It is not, however, what 
is called by that name in other parts of the country, viz., Vallisneria 
spiralis, a flowering plant not in the least related to Plectonema. REPORT OF PROFESSOR NICHOLS. 
To the Water Commissioners of the City of Boston: — 
The following table contains the results of the partial chemical ex- 
aminations of Cochituate water made in the laboratory of the Institute 
of Technology during the year from July, 1876, to July, 1877. The 
water has been uniformly of good quality and generally very free from 
any matter in suspension. 
Yours respectfully, 
WM. RIPLEY NICHOLS. 
Examination of Boston Water Supply. 
[Results expressed in Parts per 100.000.J 
B 
Nov. 4 . . . . 
tO 
CO 
Oct. 7 . . . . 
03 
o 
to 
CO 
Sept. 4 . . . . 
to 
© 
00 
B 
Aug. 4. . . . 
IB 
to 
4- 
July 7. . . . 
N 
r 
M 
a 
Date. 
0.0032 
0.0037 
0.0037 
0.0040 
0.0040 
0.0040 
Of 000 
© 
© 
© 
4- 
© 
0.0037 
0.0040 
0.0040 
0.0040 
0.0040 
0.0040 
0.0040 
0.0037 
Ammonia. 
d 
3 2 
> P 
0.0125 
0.0136 
09100 
0.0152 
0.0160 
0.0163 
0.0168 
0.0168 
0.0173 
0.0165 
© 
© 
03 
0.0176 
0.0171 
0.0171 
0.0171 
0.0173 
“ Albuminoid 
Ammonia.” 
2 * 
2 w 
? w 
M 
0 
0.0032 
0.0037 
0.0037 
o 
8 
U- 
o 
© 
o 
o 
K 
o 
0.0040 
0.0040 
© 
© 
© 
© 
0.0037 
0.0040 
© 
© 
5 
4- 
© 
0.0040 
0.0040 
0.0040 
0.0040 
0.0053 
Ammonia. 
3 
P 
H 
M 
5d 
W 
- 
0.0125 
0.0136 
egioo 
0.0149 
0.0157 
0.0163 
0.0136 
0.0160 
0.0160 
0.0160 
0.0160 
0.0165 
0.0160 
0.0163 
0.0163 
0.0157 
“Albuminoid 
Ammonia.” 
> 
■ 
? 
2.56 
2.02 
to 
00 
2.26 
2.44 
2.14 
2.06 
1.94 
2.50 
2.16 
2.42 
2.38 
2.34 
2.34 
Inorganic. 
OQ 
O 
Of I 
1.94 
• 
1.46 
1.76 
1.76 
2.10 
1.72 
bo 
00 
1.66 
1.64 
1.74 
1.78 
1.90 
1.52 
Organic and 
Volatile. 
5 
w 
w 
s 
3.96 
3.96 
• 
4.24 
4.02 
4.20 
4.24 
CO 
00 
3.82 
4.16 
3.80 
4.16 
4.16 
4.24 
CO 
03 
© 
Total at 212° F. 
G 
W 7 
Examination of Boston Water Supply. — Continued. 
Unfiltered 
Water. 
Filtered Water. 
Solid Residue. 
Date. 
Ammonia. 
“ Albuminoid 
Ammonia.” 
Ammonia. 
1 “Albuminoid 
Ammonia.” 
Inorganic. 
Organic and 
Volatile. 
Total at 212° F. 
Nov. 17 ... . 
0.0O29 
0.0141 
0.0029 
0.0141 
. . . 
. . . 
“ 28 ... . 
0.0029 
0.0141 
0.0029 
0.0141 
1.92 
1.80 
3.72 
Dec. 5 . . . . 
0.0008 
0.0141 
0.0008 
0.0136 
2.24 
1.78 
4.02 
“ 14. . . . 
0.0008 
0.0144 
0.0008 
0.0139 
2.12 
1.76 
3.88 
“ 21 ... . 
0.0021 
0.0136 
0.0021 
0.0131 
2.10 
1.82 
3.92 
“ 28 . . , . 
0.0016 
0.0139 
0.0016 
0.0136 
2.22 
1.70 
3.92 
1877. 
Jan. 4 . . . . 
0.0005 
0.0136 
0.0005 
0.0136 
2.22 
1.74 
3.96 
“ 10 ... . 
0.0005 
0.0133 
0.0005 
0.0131 
2.34 
1.86 
4.20 
“ 18 ... . 
0.0005 
0.0128 
O.OuOS 
0.0120 
2.62 
1.72 
4.34 
* * 25 • • • • 
0.0005 
0.0120 
0.0005 
0.0120 
2.74 
2.06 
4.80 
“ 31 ... . 
0.0008 
0.0120 
0.0008 
0.0115 
2.38 
2.26 
4.64 
Fob. 15 ... . 
0.0011 
0.0112 
0.0011 
0.0107 
2.82 
2.30 
5.12 
“ 22 ... . 
0.0019 
0.0109 
0.0019 
0.0101 
3.26 
2.32 
5.58 
“ 28 ... . 
0.0021 
0.0115 
0.0021 
0.0107 
3.20 
2.10 
5.30 
Mar. 8 . . . . 
0.0019 
0.0128 
0.0019 
0.0125 
2.72 
2.28 
6.00 
“ 14. . . . 
0.0016 
0.0120 
. 0.0016 
0.0115 
2.64 
2.34 
4.98 
“ 28 ... . 
0.0019 
0.0117 
0.0019 
0.0112 
2.96 
1.98 
4.94 
April 5 . . . . 
0.0019 
0.0107 
0.0019 
0.0104 
2.32 
2.04 
4.36 
“ 11 ... . 
0.0019 
0.0099 
0.0019 
0.0099 
2.68 
2.08 
4.76 
“ 25 ... . 
0.0016 
0.0120 
0.0016 
0.0115 
2.68 
2.00 
4.68 
May 2 . . . . 
0.0029 
0.0115 
0.0029 
0.0109 
2.60 
2.04 
4.64 
“ 10 ... . 
0.0024 
0.0120 
0.0024 
0.0115 
2.28 
2.04 
4.32 
» 15 ... . 
0.0024 
0.0120 
0.0024 
0.0117 
2.80 
1.68 
4.48 
“ 23. . . . 
0.0027 
0.0123 
0.0027 
0.0120 
2.48 
2.16 
4.64 
“ 31 ... . 
0.0044 
0.0120 
0.0043 
0.0120 
2.44 
1.68 
4.12 
June 6 . . . . 
0.0040 
0.0147 
0.0040 
0.0141 
2.68 
1.64 
4.32 
“ 13 ... . 
0.0056 
0.0152 
0.0056 
0.0149 ' 
2.28 
1.88 
4.16 
“ 20 ... . 
0.0048 
0.0165 
0.0048 
0.0157 
2.16 
1.72 
3.88 
“ 27 ... . 
0.0053 
0.0136 
0.0053 
0.0131 
2.56 
1.64 
4.20