72 ROCHESTER ACADEMY OF SCIENCE. [June 23, 
These samples were submitted to Dr. Harrington without any clue 
to the locality from which they were derived, he having merely tne 
identification numbers as given at the head of the table, and the follow- 
ing extract from his written report is of considerable interest with this 
understanding. 
HARVARD MEDICAL SCHOOL, CHEMICAL LABORATORY, 
Boston, Nov. 10, 1889. 
“<T cannot see anything to condemn in any of the Rochester samples, which, from 
the very close similarity in the chlorine determinations, I infer are from the same general 
source. Nos. 3 and 11 are, from a chemical standpoint, most excellent waters. In Nos. 
15 and 16 there is a marked increase in the amount of organic matter and at the same 
time a diminution in the residue. This increase appears to be from vegetable matter. 
Assuming that they are from the same general source, if the increase in organic matter 
were due to sewage contamination, we would under ordinary conditions expect a co- 
incident increase in chlorine and total residue. I regret that 1am unable to give you the 
exact determination of the hardness. One can, however, form a tolerably correct idea of 
the hardness from the fixed residue. In no one of the waters can the hardness be high; 
on the contrary the figures indicate soft waters, Nos. 15 and 16 being the two softest.” 
CHAS. HARRINGTON. 
In the meantime Dr. Ernst made bacteriological examinations of 
the waters submitted to him, and at the conclusion of his study 
forwarded the following report : 
REPORT ORVDR Hn CG eERNow: 
JAMAICA PLAIN, Dec. 3, 1889. 
November 6, 1889. Nine bottles of water received from Rochester. On the seventh 
a gelatine-saucer culture was made from each, containing ten drops of water. 
Three gelatine-plate cultures made from each specimen, five drops of water in each 
culture. (Saucers and plates were placed in the ice chest until November 11.) 
On the twelfth, an examination of the cultures made with the following results : 
WateER No. 1—(School house well) —Saucers and plates were completely liquefied. 
In both specimens were a large number of non-liquefying colonies. But on 
account of the liquefaction and the large number of colonies no count was possible, 
and no further cultures could be made. 
Water No. 2-- (Mrs. R. K. Grover well)—Precisely the same conditions as in 
No. 1, the liquefaction was so great as to prevent further wok on the specimen. 
WateR No. 3—(Lime-Kiln Gull creek at Advent church.) 
Saucer liquefied. 
Plate 1—Liquefied. 
Plate 2 —Contained 39 liquefying colonies and 160 non-liquefying 
colonies. 
Plate 3—The same as plate 2. 
The pipette used measured twenty drops to one c. c. and therefore the water 
contained about 800 colonies to one c. c. and a large number of liquefying colonies. 
