1890.] RAFTER AND MALLORY—ENDEMIC OF TYPHOID FEVER. 77 
especially if they be of many varieties—is the indication that they furnish of organic 
contamination of the water in which they are found. In this case, it would seem that the 
conclusion might be drawn—in regard to the waters marked ‘‘AA”’ and “* BB” and 
‘*FF’’—that the number of colonies of the same variety of bacteria, indicated some 
especial source of contamination, or that especial bacteria found some particularly favorable 
element for their nutrition in these waters. In any case the failure to find the typhoid- 
bacillus is not by any means a sign that it was not there originaly, or even at the time 
when the examination was made ; only, that in the latter case, the number of bacteria 
present made its detection impossible for us. ; 
HaROLD C. ERNST. 
The following is Dr. Harrington’s analysis of sample DD 
(Hendershot well) as referred to by Dr. Ernst. Results in parts per 
100,000. 
Free ammonia 0.01. 
Albuminoid ammonia 0.017. 
Chlorine 9.60. 
Relative to this sample Dr. Harrington’s comment is that it is 
‘distinctly bad.” 
Professor Lattimore gives in his analyses parts per 100,000 of 
sodium chloride, while Dr. Harrington gives chlorine in parts per 100.000. 
Mr Rafter’s results are ch/ovine in grains per U.S. gallon. In order to 
compare the results we have reduced Professor Lattimore’s determina- 
tions to chlorine in parts per 100.000, and also to grains per U. S. 
gallon. In the same way Dr. Harrington’s determinations of chlorine 
have been reduced to grains per U.S. gallon. Likewise other analyses 
made by Professors Lattimore and Leeds have been thustreated. The 
analysis of Hemlock lake water, by Professor Lattimore, given in the 
fourth series of analysis on page 78 was presented to the Common 
Council in a report on the comparative sanitary value of the waters of 
Hemlock lake and lake Ontario under date of November 22nd, | 889. 
Following is the complete analysis of Hemlock lake water as made by 
Professor Lattimore at that time, in parts per 100,000. 
Free ammonia 0.004. 
Albuminoid ammonia 0.006. 
Sodium chloride 0.50. 
Fixed residue 5-80. 
Loss on ignition 4.00. 
Total solids 9.80. 
Nitrites None. 
Nitrates None. 
