REPORT OF THE DEPARTMENT OF 
BACTERIOLOGY. 
CHLOROFORM AS AN AID IN THE STUDY 
OF MEHEK ENZYMS.* 
H. A. HARDING any L. L. VAN SLYKE. 
SUMMARY. 
1. Solubility—At 20° C. (68° F.) skim-milk is saturated by 
6.55 per ct. of chloroform by volume. Normal milk containing 
5 per ct. of fat requires an additional 1.0 per ct. of chloroform to 
produce saturation. 
II. Germicidal action.— Skim-milk fate 2 patoctanOr 
protein requires 0.2 per ct. by volume of chloroform to destroy 
the vegetative bacteria gradually and 04 per ct. to destroy 
them within 24 hours. In normal milk containing 5 per ct. of 
‘fat, I.o per ct. of chloroform destroys the vegetative’ forms 
gradually, 1.5 per ct. destroys them within 24 hours, while 2.0 
per ct. accomplishes this result within 4 hours. The spores are 
not immediately destroyed even with excessive amounts of chloro- 
form. , | 
In chloroformed cheese the germicidal action is slightly vari- 
able and a uniform destruction of the vegtative forms was not 
obtained with less than Io per ct. by weight of chloroform. 
III. Action on milk enzyms.— In skim-milk, digestion pro- 
gressed at a uniform rate in the presence of chloroform varying 
from 0.2 to 0.7 per ct. by volume. With increasing percentages 
of chloroform there was a decrease in the rate of digestion, which 
in the presence of 2.5 per ct. of chlorofrom amounted to 12 per ct. 
of that occurring in the presence of 0.7 per ct. of chloroform. 
* Reprint of Technical Bulletin No. 6. 
