SCIENTIFIC PROCEEDINGS. 



Abstracts of the Communications. 

 Thirty seventh meeting. 



The Rockefeller Institute for Medical Research. December 15, 

 ipop. President Lee in the chair. 



37 (447) 



A new method for testing the interaction of ferments and 



anti-ferments. 



By S. FELDSTEIN and R. WEIL. 



[From the Department of Experimental Therapeutics, Cornell 



Medical School '.] 



Within the past two years, the antitryptic activity of human 

 serum has been the subject of a considerable number of studies, 

 and it has apparently become established that this property of the 

 serum varies within wide limits in certain conditions of disease, 

 being characteristically increased in all cachexias, notably so in 

 cancer. Two methods have been employed in this study, which 

 are exactly the same in principle, in that they are based on the use 

 of a series of mixtures of trypsin in solution, and of the serum, the 

 end-point in the one method being denoted by the smallest quantity 

 of serum which totally inhibits the digestive action of the trypsin, 

 on a plate of coagulated beef-serum, while, in the other, it is the 

 lowest proportion of trypsin which completely digests the medium, 

 namely, a solution of casein. It is evident that by either of these 

 methods it is possible to determine only an approximate value of 

 serum, lying between the two dilutions, just above and just below 

 the so-called end-point. Moreover, the end-point itself is in 

 neither method sharply defined. If, to these uncertainties, is added 

 the fact that the media of digestion are subject to certain uncontrol- 

 lable variations, Such as the inherent differences in sera, — it will be 



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