180 Report oF THE CHimicaL DEPARTMENT OF THE 
than under either of the other two conditions. From this it 
might be inferred that 15 per ct. of ether was more favorable to 
enzyme action than 3 per ct. chloroform, but the results of the 
bacteriological analyses give some reason for believing that 
there had taken place a growth of bacteria. There had probably 
been a corresponding increase in the amount of bacterial enzyme. 
This is rendered more likely by the fact that the bacteria in this 
case were almost entirely of a single kind, which showed ability 
to grow in the presence of ether, formed spores quickly in almost 
every cell and elaborated enzyme with great freedom. 
This experience has made us slow to accept as trustworthy 
any results obtained with the use of ether, when the conditions 
are not constantly controlled by quantitative examination of the 
bacterial content. 
COMPARISON OF EFFECTS OF CHLOROFORM AND FORMALIN UPON 
ACTIVITY OF ENZYMES. 
Jensen! in a suggestive article on the enzymes of cheese ripen- 
ing has called attention to the use of 0.1 per ct. of formalin in 
studying their activity. Babcock and Russell!’ have stated that 
comparatively small amounts of this substance completely 
inhibit enzyme activity. The use of even the amounts recom- 
mended by Jensen is to be looked upon with suspicion until the 
influence of formalin upon enzyme action is more fully 
investigated. 
In order to facilitate comparisons at some future time, we give 
the results of parallel examinations of four samples of milk con- 
taining respectively 4 per ct. of chloroform and 0.1 per ct. of 
formalin by volume. Unfortunately the strength of formalin 
was not redetermined but it was the 40 per ct. article of 
commerce, 
The milk in this case was obtained from the four quarters of a 
single cow at one milking. The flank and udder were brushed 
and moistened. The hands of the milker were smeared with 
vaselin and the milk was caught in four-inch glass funnels lead- 
“Jensen. See No. 9. 
“Babcock and Russell. Anm Rept. Wis. Exp. Sta. 15:77 (1898). 
