PROFESSOR W. R. NICHOLS 
ON THE 
BOSTON WATER SUPPLY. 
[From the Fourth Annual Jteport of the Foston Water Foard, City 
Document ATo. 108, 1880.] 
To H. M. Wightjian, Esq., City Engineer: — 
Dear Sir,—I submit herewith in tabular form the results of 
such chemical examinations of Cochituate and Mystic water as have 
been made in my laboratory during the past year. The analyti- 
cal work has been performed under mv direction by Mr. W. W. 
Macfarlane, S.B., and I have full confidence in the accuracy of 
the results. 
Cochituate Water. 
The quality of the water delivered from the Cochituate works 
has been generalh’ good. As in the case of all surface waters, a 
good filter will remove, at any time, more or less of animalcules 
and vegetable fragments, but there is no evidence that the presence 
of the small quantity of these foreign substances in the water 
actually used for drinking gives to it an}T unwholesome quality. 
During a portion of the year a very considerable amount of water 
has been contributed by the Sudbury-river works ; and, as a result, 
at times the water as drawn in the city has been quite strongly 
colored. For a few days, during which, as I understood, experi- 
ments were being made on the flow of the water in the aqueduct, 
the water had rather a marked unpleasant taste, evidently due to 
the vegetable matter taken up in the storage basins. The bene- 
ficial effects of exposing a water of this character to the air, in an 
open conduit or b}T passing through a reservoir, are very marked. 
Table I. contains the results of the examination of the water as 
drawn in the Laboratory of the Massachusetts Institute of Tech- 
nology. The method employed is that known as Frankland’s, some 
description of which was given in the last report of the Water 
Board. For the benefit of those to whom this method is yet un- 
familiar, I may state that it consists in evaporating a certain quan- 
tity of the water to dryness, under suitable conditions, and sub- 
jecting the dry residue which remains to a process of organic 
anatysis, in a closed vessel, in such a manner as to convert all* the 
carbon and nitrogen of the organic matter into gaseous substances, 
which are collected and measured. The carbon and nitrogen are 
spoken of as organic carbon and organic nitrogen respectively, and 
they are sometimes taken together and spoken of as the organic 
elements. The method is difficult and tedious, requiring the use of 
expensive and frangible apparatus, and consuming considerable 
time ; for these reasons it can never be popular. Moreover, as is 
the case with every method employed for obtaining indications of 2 
the amount and character of the organic matter in the water, the 
results must be interpreted by a knowledge of the source from 
which the water is derived, and of its surroundings. It must be 
borne in mind, moreover, that the sum of the amounts of organic 
carbon and organic nitrogen does not represent the actual amount 
of organic matter present, for most organic substances which occur 
in natural waters contain in addition a larger or smaller amount 
of oxygen and of hydrogen ; how much, in any particular case, we 
cannot tell. In interpreting the results it is felt that considerable 
importance attaches to the relative proportion of carbon to nitrogen, 
for it is, in general, true that organic matter of vegetable origin 
contains a larger proportion of carbon, while organic matter of 
animal origin contains a larger proportion of nitrogen.1 
(Results expressed as so many parts by weight in 100,000 parts by weight of the water.) 
Table I. — Examination of Boston Water. 
Date. 
Temperature 
in Centigrade 
Degrees. 
Organic 
Carbon. 
Organic 
Nitrogen. 
Sum of the 
Organic 
Elements. 
Ratio. 
Carbon 
Nitrogen. 
1879. 
June 26 
0.386 
0.022 
0.408 
17.5 
July 2 
0.377 
0.026 
0.403 
14.5 
“ 9 
0.376 
0.030 
0.406 
12.5 
“ 23 
22.1 
0.384 
0.048 
0.432 
8.0 
“ 31 
23.2 
0.339 
0.029 
0.368 
11.7 
Aug. 7 
24.1 
0.398 
0.029 
0.427 
13.7 
“ 14 
26.7 
0.405 
0.027 
0.432 
15.0 
“ 21 
20.7 
0.432 
0.053 
' 0.485 
8.2 
“ 28 
20.5 
0.365 
0.073 
0.438 
5.0 
Sept. 4 
20.3 
0.401 
0.063 
0.464 
6.4 
“ 11 
20.1 
0.436 
0.042 
0.478 
10.4 
“ 18 
19.5 
0.443 
0.072 
0.515 
6.1 
“ 25 
17.9 
0.444 
0.069 
0.513 
6.4 
Oct, 2 
17.7 
0.404 
0.065 
0.469 
6.2 
“ 9 
18.9 
0.386 
0.038 
0.424 
10.1 
“ 16 
# 
16.9 
0.409 
0.034 
0.443 
12.0 
“ 23 
15.5 
0.367 
0.049 
0.416 
7.5 
“ 30 
12.3 
0.402 
0.049 
0.451 
8.2 
Nov. 21 
8.8 
0.407 
0.062 
0.469 
6.6 
Dec. 4 
6.8 
0.449 
0.042 
0.491 
10.7 
“ 19 
3.8 
0.450 
0.051 
0.501 
8.8 
1 For a fuller discussion of Frankland’s method, see Report of Massachusetts State 
Board of Health, Lunacy and Charity, 1880. Department of Health, pp. Ill, et seq. 3 
Table I. — Continued 
Date. 
Temperature 
in Centigrade 
Degrees. 
Organic 
Carbon. 
Organic 
Nitrogen. 
Sum of tbe 
Organic 
Elements. 
Ratio. 
Carbon 
Nitrogen. 
1880. 
Jan. 1 
3.3 
0.500 
0.055 
0.555 
9.0 
“ 16 
3.3 
0.545 
0.064 
0.609 
8.5 
“ 23 . , 
0.694 
0.064 
0.758 
10.8 
“ 31 
3.6 
0.614 
0.041, 
0.655 
15.0 
Feb. 5 
2.9 
0.659 
0.061 
0.720 
10.8 
“ 9 
4.0 
0.668 
0.072 
0.740 
9.3 
“ 12 
0.723 
0.063 
0.786 
11.5 
“ 19 
3.0 
0.592 
0.051 
0.643 
11.6 
“ 25 
3.1 
0.526 
0.064 
0.590 
8.2 
Mar. 4 
6.3 
0.582 
0.047 
0.629 
12.4 
“ 11 
4.2 
0.443 
0.071 
0.514 
6.2 
“ 18 
6.8 
0.413 
0.060 
0.473 
6.9 
“ 26 
4.2 
0.438 
0.037 
0.475 
11.8 
April 1 
4.8 
0.368 
0.046 
0.414 
7.9 
“ 9 
0.446 
0.048 
0.494 
9.3 
“ 16 
9.2 
0.397 
0.044 
0.441 
9.0 
“ 22 
9.8 
0.360 
0.047 
0.407 
7.7 
May 6 
13.2 
0.325 
0.046 
0.371 
7.1 
“ 13 
15.6 
0.361 
0.063 
0.424 
5.7 
“ 21 
15.8 
0.423 
0.034 
0.457 
12.4 
“ 28 
18.8 
0.447 
0.075 
0.522 
6.0 
Mean of 42 samples 
0.452 
0.051 
0.503 
8.9 
Mtstic Water. 
The samples of water have been furnished me from the 
office in Charlestown. The results of the examination are presented 
in Table II., together with the record of the examination of samples 
taken fi-Qin the Mystic pond itself during a portion of the year. 
These samples were taken two feet below the surface, at a point 
some distance from the shore where the water is usually about 75 
feet deep. 4 
Tarle II. — Examination of Mystic Water. 
(Results expressed as so many parts by weight in 100,000 parts by weight of the water.) 
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Table II. — Continued. 
Date. 
Locality. 
Organic 
Carbon. 
Organic 
Nitrogen. 
Sum of the 
Organic 
Elements. 
Ratio. 
Carbon 
.Nitrogen. 
Ammonia. 
<l Albumin- 
oid Ammo- 
nia.” 
Total 
Solids. 
Feb. 12 . . 
Charlestown . . 
0.442 
0.060 
0.502 
7.4 
0.037 
0.018 
11.4 
“ 17 . . 
Mystic Pond . . 
0.471 
0.067 
0.628 
8.3 
0.025 
0.021 
8.8 
“ 19 . . 
Charlestown . . 
0.421 
0.044 
0.465 
9.6 
0.035 
0.020 
10.1 
“ 26 . . 
“ 
0.34G 
0.039 
0.385 
8.9 
0.031 
0.016 
10.4 
March 4 . . 
“ 
0.347 
0.039 
0.386 
8.9 
0.033 
0.016 
9.9 
“ 6 . . 
Mystic Pond . . 
0.349 
0.040 
0.389 
8.7 
0.044 
0.017 
10.3 
“ 11. . 
Charlestown . . 
0.356 
0.062 
0.418 
5.7 
0.027 
0.016 
9.7 
“ 19. . 
“ 
0.314 
0.060 
0.374 
5.3 
0.027 
0.013 
9.9 
“ 25. . 
“ 
0.322 
0.062 
0.384 
5.2 
0.027 
0.015 
10.4 
April 1 . . 
“ 
0.309 
0.045 
0.354 
6.9 
10.3 
“ 5. . 
Mystic Pond . . 
0.273 
0.046 
0.319 
6.9 
0.040 
0.016 
10.1 
“ 9 . . 
Charlestown . . 
0.297 
0.044 
0.341 
6.8 
0.024 
0.015 
10.7 
“ 14. . 
Mystic Pond . . 
0.041 
0.017 
10.2 
“ 15 . . 
Charlestown . . 
0.361 
0.054 
0.415 
6.7 
0.020 
0.017 
10.5 
“ 22. . 
“ 
0.297 
0.060 
0.357 
4.9 
0.013 
0.016 
10.8 
“ 29 . . 
“ 
. . 
10.4 
May 3 . . 
Mystic Pond . . 
0.386 
0.061 
0.447 
6.3 
0.037 
0.020 
10.2 
“ 6 . . 
Charlestown . . 
0.256 
0.054 
0.310 
4.7 
0.007 
0.017 
10.7 
“ 12 . . 
Mystic Pond . . 
0.366 
0.082 
0.448 
4.4 
0.031 
0.021 
10.6 
“ 13. . 
Charlestown . . 
0.333 
0.068 
0.401 
4.9 
0.008 
0.016 
10.9 
“ 20 . . 
“ 
0.359 
0.073 
0.432 
4.9 
0.008 
0.016 
10.5 
“ 24. . 
Mystic Pond . . 
0.332 
0.046 
0.377 
7.4 
0.031 
0.021 
10.6 
“ 27 . . 
Charlestown . . 
0.358 
0.061 
0.419 
5.9 
0.009 
0.021 
10.8 
June, ’79, ) 
to > 
May, ’80, ) 
Charlestown ) 
Mean of 35-39 J 
samples . . ) 
0.392 
0.065 
0.457 
6.0 
0.012 
0.018 
9.9 
Oct., ’79, ) 
to > 
May ’80, 1 
Mystic Pond "] 
(surface.) 1 
Mean of 12-14 [ 
samples . . J 
0.349 
0.064 
0.403 
6.5 
0.028 
0.018 
10.0 
Oct., ’79, ) 
to 1 
May, ’80, ) 
Charlestown ) 
Mean of 19-20 l 
samples1 . . ) 
0.339 
0.053 
0.392 
6.6 
0.019 
0.015 
9.8 
1 This average is made up from the samples drawn in Charlestown during the time within 
which samples from the pond have also been examined. 
In studying the figures in the foregoing table we see very clearly 
one fact to which I have frequently called attention, namely, the 
great variation to which surface-waters are subject, and especially 
in respect to the organic matter which they contain. On this 
account it is seldom possible to form a just idea of the general 6 
character of such a water from a single examination. This varia- 
tion is rendered very large in the present instance because, during 
the summer, there was in Mystic pond, and in the water as drawn 
in the city, a very large amount of certain microscopic plants 
belonging to the algce, and similar to those which occurred in 
such quantities in Horn pond in 187G.1 A full description of these 
plants, with a plate, occurs in the Report of the State Board of 
Health, Lunacy, and Charity, for 1880. 
In order that the effect of their presence may appear more clearly, 
I have prepared Table III., in which we have the results presented, 
first in monthly averages, and then in averages for certain periods 
into which there seemed to be a natural division. The algce became 
numerous enough to awaken complaint and apprehension after the 
middle of July, and the trouble was at its height in the latter part 
of July and during August. 
Table III. — Examination of Mystic Water. 
(Results expressed in parts in 100,000.) 
Date. 
Number of Samples. 
Sum of the 
Organic 
Elements. 
“Albuminoid 
Ammonia.” 
1870. 
June 
Mean of 2 samples 
0.478 
July 
“ “ 4 “ 
0.775 
0.0351 
August 
“ “ 4 “ 
0.605 
0.026 
September 
“ “ 3 “ 
0.448 
0.020 
October 
“ “ 5 “ 
0.333 
0.014 
November 
u a 2 “ 
0.393 
0.011 
December 
“ “ i “ 
0.297 
0.011 
1880. 
January 
“ “ 2 “ 
0.364 
0.012 
February 
“ “ 3 “ 
0.469 
0.019 
March 
“ “ 4 “ 
0.390 
0.015 
April 
“ “ 4 “ 
0.389 
0.0162 
May 
“ “ 4 “ 
0.390 
0.017 
1870. 
June 19 — July 3- . . . 
“ “ 3 “ 
0.486 
July 10—Aug. 7 . . . 
“ “ 4 “ 
0.852 
0.034 
Aug. 14 — Sept 11 . . . 
“ “ 4 “ 
0.526 
0.022 
Sept. 18 —May 27, ’80 . 
“ “ 28 “ 
0.389 
0.016 
xMean of two samples. 
2 Mean of three samples. 
1 See First Annual Report of Boston Water Board, 1877. 7 
Even in the absence of abnormal condition such as was 
caused this summer by the growth of algce, there is at times a con- 
siderable variation in the amount and character of the organic 
matter in the water, as, for instance, in October, 1879, when, on 
the 9th and 16th of the month, the nitrogen was very much below 
the usual amount; as again on December 4th. That such changes 
should take place is not at all surprising, although Ave may not be 
able to explain the reason why in each particular case. The water 
is taken from near the surface of the pond, flows in a conduit for 
some distance to the pumping-station, is pumped into an open res- 
ervoir, and thence distributed into the city. We know that, the 
organic matter in natural water undergoes change with greater or 
less rapidity, owing to the difference of temperature, to the action 
of the wind, to the length of time during which the water is exposed 
to the sun and air in the reservoir, and to other such causes. 
That the considerable variation in the amount and relative pro- 
portion of the organic carbon and organic nitrogen is not peculiar 
to M}'stic water, may be seen from Table IV., compiled from the 
Sixth Report of the Rivers Pollution Commission, which shows 
the variation in the water of the several companies which supply 
the city of London, Eng. The same thing is true in other places 
as well. 
Table IV.— Variation in Monthly Samples of London Water, 1873. 
(Results expressed in parts in 100,000.) 
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Samples. 
a 
In order to judge of the general character of the Mystic water, 
as shown by the results of Frankland’s method of analysis, we have 
the necessary material in Table V., from which it appears that the 
total amount of organic matter, as indicated by the organic carbon 
and nitrogen, would be somewhat less than in Cochituate, were it 
not for the increase brought about by the development during the 
summer months of the algce, to which allusion has been made. It 8 
appears, however, that, on the whole, there is a larger proportion 
of nitrogen in the Mystic than in the Cochituate water; and this 
agrees with what we know of the character of the respective water- 
sheds. Considering also that the total dissolved substances, 
organic and inorganic, amount to twice as much in the Mystic as 
in the Cochituate supply, we must regard the latter as the better 
water; the examination shows, however, as far as chemical exam- 
ination can show, that, in spite of the polluting influences which 
have been at work in the ponds and streams supplying Mystic 
pond, the water, in its normal condition, is still good, and well 
suited for domestic supply. 
There is one other point to which allusion might be made. In 
pursuit of some inquiries in which I have been engaged, I have had 
made a number of chemical examinations of the water of Mystic 
pond at the depth of eighteen feet, and also at the bottom of the pond. 
Since January we have been able, by having a buoy anchored in 
the pond, to take the samples at the same point where the water 
is seventy-five feet deep. Previous to that time we did not always 
succeed in finding the same spot, and some of the bottom samples 
were taken at a depth of fifty feet only. Being- unable for the 
present to prosecute the research which I had planned, I should 
like to put the results thus far obtained on permanent record. 
They are included in tables VI. and VII. 
Respectfully submitted, 
WM. RIPLEY NICHOLS. 
Massachusetts Institute oe Technology, June, 1880. 9 
Table V. — Comparison of Mystic and other Waders. 
(Results expressed in parts in 100,000.) 
Date. 
Description. 
Organic Car- 
bon. 
Organic Ni- 
trogen. 
Sum of the 
Organic 
Elements. 
Ratio. 
Caibon 
Nitrogen. 
June, 1879—May, 1880 
Mystic water as drawn in 
Charlestown. Mean of 39 
samples 
0.392 
0.065 
0.457 
6.0 
Sept. 18, 1879—May 
27, 1880 
Mystic water as above, — omit- 
ting the samples taken while 
the algoB were abundant. 
Mean of 28 samples 
0.336 
0.053 
0.389 
6.3 
Jan., 1879—June, 1879 
Boston water (CochituateLake 
and Sudbury River). Mean 
of 22 samples1 
0.408 
0.052 
0.460 
7.9 
June, 1879—May, 1880 
Boston water. Mean of 42 
samples 
0.452 
0.051 
0.503 
8.9 
Jan., 1879—June, 1879 
FreRli Pond,2 Cambridge. Mean 
of 11 samples 
0.417 
0.074 
0.491 
5.6 
May, 1873—May, 1874 
Loch Katrine water,3 Glasgow, 
Scotland. Mean of 12 sam- 
ples 
0.197 
0.018 
0.215 
10.9 
/ 
Unpolluted surface waters.4 
Mean of 195 samples .... 
0.322 
0.032 
0.354 
10.0 
1 Third Annual Report of Boston Water Board, 1879. 
2 These samples were taken from the pond itself, and the results do not claim to represent 
the water as delivered in Cambridge. 
3 Sixth Report of Rivers Pollution Commission, p. 347. 
4 Sixth Report of Rivers Pollution Commission, p. 425. 10 
Table VI. — Examination of Water in Mystic Lake. 
(Results expressed in parts in 100,000.) 
Date. 
Depth below Surface. 
Ammonia. 
“Albuminoid 
Ammonia.” 
Total Solids 
Oct. 18, 1879 . 
18 feet 
0.001 
0.017 
9.1 
Nov. 8, 1879 . 
it 
0.008 
0.011 
9.6 
Nov. 15, 1879 
ii 
0.008 
0.013 
9.6 
Nov. 22, 1879 
ii 
0.015 
0.013 
9.8 
Dec. 8,1879 . 
(( 
0.011 
0.011 
9.6 
Jan. 30, 1880 
(1 
0.031 
0.016 
11.1 
Feb. 6,1880 . 
ii 
0.035 
0.019 
11.1 
Feb. 17,1880 
ii 
0.041 
0.016 
10.8 
March 6, 1880 
ii 
0.040 
0.016 
10.4 
April 5, 1880 
ii 
0.040 
0.013 
10.2 
April 14, 1880 
ii 
0.040 
0.016 
10.4 
May 12, 1880 
it 
0.032 
0.016 
10.5 
May 24, 1880 
ii 
0.040 
0.016 
10.6 
June 3, 1880 . 
ii 
0.036 
0.017 
10.3 
Average .... 
0.027 
0.015 
10.2 11 
Table VII. — Examination of Water in Mystic Lake. 
(Results expressed in parts in 100,000.) 
Date. 
Depth below 
Surface. 
Organic 
Carbon. 
Organic 
Nitrogen. 
Sum of Organic 
Elements. 
Ammonia. 
“ Albuminoid 
Ammonia.” 
Total Solids. 
Oct. 
18,1879 . . . 
69 feet. 
0.007 
0.011 
7.8 
Nov. 
8, “ ... 
50 “ 
0.307 
0.047 
0.354 
0.009 
0.011 
9.6 
Nov. 
15, “ . . . 
60 
0.606 
0.106 
0.712 
0.023 
0.027 
11.6 
Nov. 
22, “ . . . 
50 “ 
0.309 
0.047 
0.356 
0.016 
0.017 
9.6 
Dec. 
8, “ . . . 
54 “ 
0.288 
0.041 
0.329 
0.011 
0.008 
9.7 
Jan. 
30, 1880 . . . 
70-78 “ 
0.403 
0.033 
0.436 
0.027 
0.016 
11.8 
Feb. 
6, “ . . . 
70-78 “ 
0.514 
0.071 
0.585 
0.080 
0.019 
11.8 
Feb. 
17, “ . . . 
70-78 “ 
0.440 
0.096 
0.536 
0.075 
0.017 
11.5 
March 
6, “ . . . 
70-78 “ 
0.312 
' 0.032 
0.344 
0.040 
0.015 
9.5 
April 
5, “ . . . 
70-78 “ 
0.287 
0.037 
0.324 
0.041 
0.013 
10.2 
April 
14, “ . . . 
70-78 “ 
0.295 
0.086 
0.381 
0.043 
0.017 
10.3 
May 
3, “ . . . 
70-78 “ 
0.048 
0.019 
10.1 
May 
12, “ . . . 
70-78 “ 
0.338 
0.063 
0.401 
0.064 
0.016 
10.3 
May 
24, «... 
70-78 “ 
0.363 
0.083 
0.446 
0.064 
0.015 
10.5 
June 
3, “ . . . 
70-78 “ 
0.318 
0.077 
0.395 
0.049 
0.016 
10.6 
Average at bottom . 
0.368 
0.063 
0.431 
0.040 
0.016 
10.3 
Average at 18 ft. from top (Table VI.) . 
0.027 
0.015 
10.2 
Average at top during the same time, 
Oct., ’79—June, ’80 
0.349 
0.054 
0.403 
0.028 
0.018 
10.0 
Average as drawn in Charlestown dur- 
ing the same time 
0.339 
0.053 
0.392 
0.019 
0.015 
9.8