272 
IOWA ACADEMY OF SCIENCES. 
cate unusually good water, with the exception that in the 
Curtiss well and the Sexton well gas was produced, but 
this undoubtedly came from the surface soil. The spring 
water showed no gas whatever, nor was any obtained from 
the hydrant which was next to the spring. The samples 
and plates were carefully plated. 
BACTERIA FOUND IN OTHER WATER SUPPLIES. 
We have found quite commonly in all of our waters the 
B. liquefaciens-fluorescens. The Tyrothrix of Duclaux is 
certainly also common. Most attention has been given to 
the chromogenes. The common genera of Bacillus and 
Micrococcus w T ere represented, and of the these the Micro- 
cocci were found more frequently than the Bacilli of these 
Micrococcus roseus-fiavus , Hefferan, M. agilis , A. Cohn, and 
others were found. 
BACILLUS TYPHOSUS IN WATER. 
Now t , as to the relative vitality of Bacillus typhosus in 
water; many determinations have been made, and it 
would not be strange if the Bacillus typhosus should not be 
found in water. 
It is usually held by sanitarians that water is the most 
frequent source of infection. The evidence of B. typhosus 
in water, in most cases, is circumstantial; but I recall a 
case where Dr. Ravold found it in Mississippi river water, 
and bacteriological journals report cases of its occurrence 
in wells and streams, but the reported findings of the 
organism under such circumstances are not numerous. It 
is very evident that the typhoid fever bacillus will not 
grow in the ordinary media with other pathogenic organ- 
isms, nor are the special media much more satisfactory. 
It is evident from the results obtained from several investi- 
gators that not much can be expected from the organism 
after four weeks. It is certain that the typhoid fever 
organism will not multiply freely in water. 
MILK AS A SOURCE OF CONTAMINATION. 
As to the bacteria found in the milk supply, an investi- 
gation has been made, but this work was not completed, 
