174 Report oF THE CHEMICAL DEPARTMENT OF THE 
IV. EFFECT OF CHLOROFORM, ETHER AND FORMA- 
LIN ON THE ACTION OF ENZYMES. 
In an investigation of this kind a prime necessity is a means 
of totally suppressing the action of germ life. It is equally 
important that the action of the agents employed shall not be 
so violent as to alter the enzymes @r the casein. 
The work of Babcock and Russell has suggested two sub- 
stances suitable for this purpose, ether and chloroform. Of the 
two we have used chloroform almost exclusively for several 
reasons: (1) As an anesthetic it is more efficient; (2) its pro- 
portion in any mixture can be quantitatively determined with 
approximate accuracy by chemical analysis; (8) the amount 
required to prevent germ growth does not so largely increase 
the bulk of the mixture; (4) being less volatile, there is less loss 
in sampling materials under investigation; (5) it is not inflam- 
mable. 
In all our work with solutions it has been our aim to mix 
carefully by shaking at least once a day during the entire course 
of the experiment. Too much stress cannot be laid upon this 
point, since mixtures of milk with ether or chloroform tend to 
separate on standing and thereby produce conditions favoring 
the germination of spores in certain portions of the mixture. 
EFFECT OF VARYING PERCENTAGES OF CHLOROFORM ON ENZYME 
ACTIVITY. 
Since the relation of chloroform to the activity of these 
enzymes has not been investigated, except in a very general way 
by Babcock and Russell, the following study of its action on 
galactase and bacterial enzymes was made. 
Duplicate bottles of separator skim-milk containing only a 
trace of fat were prepared containing 2.5, 5, 10, 20 and 30 per ect. 
of chloroform by volume. These bottles were kept at 60° F. 
(15.5° C.), and examined both chemically and bacteriologically. 
