1890. | RAFTER AND MALLORY-—-ENDEMIC OF TYPHOID FEVER. 83 
at Springwater village may, if all the conditions are favorable, be dis- 
tributed to water consumers in Rochester within thirty-six hours. 
In further presentation of this view it is but fair to state, however, 
that the actual passage of typhoid or other disease germs from the head 
of Hemlock lake to the foot, and thence into the conduit in the manner 
indicated, would require that during the translation, from head of lake 
to foot, they remain at or near the surface, and after arriving at the 
foot sink to a depth of about thirty feet, that being the depth from which 
the conduit takes water. This additional necessary condition makes 
the contingency somewhat more remote than would appear at first 
glance, and we desire to be understood as saying, only, that as the 
result of studying the physical features of the case, we deem it not at 
all improbable, that, with the conditions favorable, disease germs may 
pass from Springwater village to the city of Rochester in thirty-six 
hours. 
In the present state of biological analysis it would not be impossible 
to make an actual demonstration, not, indeed, by placing pathogenic 
bacteria in the Springwater creek, but by planting harmless varieties 
which at a given time are known by actual trial to be absent; and by 
the bacteriological examinations of samples selected at various points 
determine the rate of progress towards the city, increase or decrease of 
numbers, and other questions likely to aid in a solution of the general 
problem. Such an examination could be carried on in conjunction 
with a study of the,contamination of the Springwater creek as already 
indicated, and we suggest as being of great practical value, not only to 
the city of Rochester but to all municipalities with public water supplies, 
that the Executive Board, as being by law the body having charge of 
everything relating to the water works, make an investigation of the 
matters here indicated. 
In continuation of the view already advanced that septic bacteria 
are inimical to pathogenic bacteria, we call attention to the conSiderable 
number of harmless forms present in the samples of Hemlock lake 
water submitted to Dr. Ernst. Referring to his report we find that the 
samples of Hemlock lake water taken from the lake itself contained 
4,000 bacteria per c. c., while as already noted the two samples from 
the Lime-Kiln Gull creek contained 800 and 1,000 colonies per c. c. 
respectively, and possibly the fact of the presence of these large 
numbers of septic forms is the reason why the city of Rochester escaped 
any serious effects from the endemic of typhoid fever at Springwater 
last fall. That we did escape such serious effects is clearly indicated 
