New York AGRICULTURAL EXPERIMENT STATION. 61 
Germicidal value of chloroform.—All determinations of the 
~ action of chloroform must be carefully guarded against loss of 
chloroform by evaporation. In working with small percentages 
the air space in the container must be small. 
Vegetative germs are very susceptible to the action of chloro- 
form’ while spores are extremely resistant. | 
In peptone bouillon, 0.1 per ct. of chloroform by volume is 
sufficient to prevent growth. In skim-milk this is sometimes 
accomplished by 0.2 per ct., but 0.3 per ct. is often required while 
0.4 per ct. destroys the vegetative forms within 24 hours. . 
In normal milk containing 5 per ct. of fat, I.o per ct. of chlo- 
roform produces an immediate reduction of the germ content, 1,5 
per ct. destroys the vegetative forms within 24 hours, while 2.0 
per ct. kills them within 4 hours and 2.5 per ct. accomplishes this 
within Io minutes. 
’ The chloroform which dissolves in the fat and settles to the 
bottom is, for all germicidal purposes, removed from the milk. 
The explanation for the observed increase in the germicidal 
action, on the addition of chloroform above that required for 
the saturation of the fat and the milk serum, is not clear, since 
this excess of chloroform also tends to settle to the bottom. 
However, during the short period in which it manifested its 
_activity, it was largely in suspension, due to repeated shaking 
of the milk. 
The results with chloroformed cheddar cheese were somewhat 
variable, indicating the action of factors which have not been 
recognized and measured. The lowest percentage tested, 5 per 
ct. by weight, prevented growth with the exception of the forma- 
tion of occasional colonies. Similar colonies were occasionally 
found in cheese containing as much as Io per ct. of chloroform 
by weight. | 
Effect upon enzym action.—With percentages of chloroform so 
low that acid formation is not prevented, the digestive action 
of milk enzyms is less rapid than when more chloroform is used. 
This is undoubtedly due to the inhibiting effect of the acid 
rather than to any stimulating action of higher percentages of 
chloroform. In skim-milk a retarding action upon the enzyms 
becomes evident with amounts between 0.7 and 1.0 per ct. This 
retardation practically reaches its maximum with 2.5 per ct. of 
chloroform, when it amounts to 12 per ct. of the amount of 
digestion that occurred in the presence of 0.7 per ct. or less of 
.. chloroform. 
