New YorK AGRICULTURAL EXPERIMENT STATION. 143 
STUDIES WHEREIN THE ENZYM WAS ISOLATED BY 
THE USE OF GERMICIDES. 
The preceding results were satisfactory so far‘as they went, 
but it was manifestly desirable to find some simpler method 
of procedure. Two serious objections to the preceding meth- 
ods should be eliminated if possible, namely, first, that pre- 
cautions are necessary to insure the sterility of the broths 
during prolonged study subsequent to filtration; and, second, 
the ever-present danger that the method used to eliminate the 
organism may at the same time remove or weaken the enzym. 
It seemed probable from the experience of others who have 
studied similar enzyms that some chemical added to the cul- 
tures would kill or wholly inhibit the bacillus without de- 
stroying the enzym or interfering with its activity. With this 
hope, trial was made of additions of formalin, phenol, thymol, 
and chloroform, respectively, to beef broth cultures. In con- 
sidering the results reference was also made to related experi- 
ments, to be discussed in detail later, where similar additions 
of these chemicals have been made to solutions of the enzym- 
containing alcoholic precipitates. 
FORMALIN. 
The relation of formalin, both to the life of the organism 
and to the activity of the precipitated enzym, has been deter- 
mined. It has been found that both the organism and the 
enzym are extremely sensitive to this chemical. Since, how- 
ever, the organism is more so it is possible so to gage the 
amount as to sterilize the broth and leave the enzym active. 
These conclusions are based upon experiments made by the 
addition of varying proportions of formalin, both to the beef 
broth cultures and to solutions of the precipitated enzym. 
Some hundreds of such additions have been made to beef broth 
cultures, including the following strengths, and numerous 
trials each of many of them: Formalin, 0.03%, 0.06%, 
0.08%, 0.095%, 0.18%, 0.33%, 0.46%, 0.57%. 
The detailed account of a single series will suffice to explain 
the general method and results. All this work was carried on 
at temperatures of 18°—22° C. 
