30 REPORT OF DEPARTMENT OF BACTERIOLOGY OF THE 
Increasing the percentage of chloroform from 2.5 to 30 per ct. 
did not retard the rate of digestion much more than did 2.5 
per.ct: 
IV. Action on milk proteids.— Chloroform above the amounts 
required to saturate the milk settles to the bottom carrying down 
a portion of the casein. This is observable as a white, opaque 
layer. 
INTRODUCTION. 
The announcement in 1897 by Babcock & Russell (1) that an 
enzym inherent in milk, later called by them galactase,? was 
a considerable factor in cheese-ripening pomptly attracted the 
attention of all students of this problem. The work of other 
investigators? has apparenly confirmed what Babcock & Russell 
early suggested, namely, that milk contains a mixture of enzyms. 
A record of our attempts to determine the action of chloroform 
when used in the study of these enzyms is given in this bulletin. 
In 1899 the problem of cheese-curing was assigned to the co- 
operative activities of the Dairy, the Chemical and the Bac- 
teriological departments. The results of their investigations 
have appeared in a series* of bulletins of which this is a 
continuation. ‘The action of chloroform was briefly discussed 
in Bulletin 203, which also included some observations on the 
action of ether. 
Early in their study of milk enzyms, Babcock & Russell(3) 
tested the action in milk of benzol, chloroform, toluol, xylol, 
analin, arsenious acid, oil of organum, thymol, sodium fluoride,. 
phenol, phenol and sodium chloride, oil of cloves, oil of cassia, 
oil of Ceylon cinnamon, turpentine and oil of mustard. They 
recommended only four of these substances — chloroform, ether, 
benzol, toluol — for the study of milk enzyms and of these they 
preferred chloroform. While we have used ether or formalde- 
*The numbers in parenthesis refer to the bibliography at the end of the 
bulletin, in which the names of authors are arranged alphabetically, with 
different articles by the same author numbered consecutively. 
? Babcock, S. M.; Russell, H. L., & Vivian, A. Properties of galactase, 
a digestive ferment of milk. Wis. Agr. Exp. Sta. Rept., 15: 77-86. 1808. 
> Vandevelde, A. J. J. Les enzymes du lait de vache. Revue genérale du 
Lait, 6: 361-370; 385-397; 414-422. 1907. Good bibliography. 
*N. Y. Agr. Exp. Station Bulletins 203, (1901); 214, 215, 219 (1902); 
231, 236, 237 (1903); 245 (1904); 261, 263 (1905); Technical Bulletins 3 
(1906) ; 4, 5 (1907). 
