174 Report of the Chemical Depautmejst of the 



lY. EFFECT OF CHLOROFOR^r, ETITER AND FOR^MA- 

 LIN ON THE ACTION OF ENZYMES. 



In an investigation of tbis kind a prime necessity is a means 

 of totally suppressing the action of genu life. It is equally 

 important that the action of the agents employed shall not be 

 so violent as to alter the enzymes Qr the casein. 



The worlv of Babcock and Russell has suggested two sub- 

 stances suitable for this jjurpose, ether and chloroform. Of the 

 two we haA'e used chloroform almost exclusively for several 

 reasons: (1) As an auipsthetic it is more efficient; (2) its pro- 

 portion in any mixtm^e can be quantitatively determined with 

 approximate accuracy by chemical analysis; {?>) 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 ])re])ar(Hl containing 2.5, 5, 10, 20 and 30 per ct. 

 of chloroform by volume. Th(^se bottles were kept at 00° F. 

 (15.5° C.j, and examined both chemically and bucteriologically. 



