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Scientific Proceedings (125) 



same result is obtained when such mixtures are treated with ethyl 

 alcohol. These experiments justify the conclusion that the in- 

 hibitory action of serum on trypsin is in the nature of an inter- 

 ference phenomenon. That is to say, that the serum protein, 

 either by virtue of a chemical reaction with the casein or a simple 

 mechanical process acts as a protective colloid. This conclusion, 

 however, does not entirely rule out the possibility that a chemical 

 reaction takes place between trypsin and serum which is readily 

 dissociable. 



In the communication cn trypsin alluded to above 1 , I stated 

 that the ferment appears to be of a strongly acid character. 

 As is known it has a positive electric charge, whereas serum 

 albumin which is chiefly concerned in the anti-tryptic phenom- 

 enon, is said to have a negative charge, so that a reaction be- 

 tween the two is conceivable. 



As to the biologic significance of the anti-tryptic action of 

 serum, I will say only a few words at the present time. Serum 

 possesses diastatic and lipolytic ferments; tryptic ferments on 

 the other hand are not ordinarily demonstrable. Because of the 

 anti-tryptic action, failure to demonstrate trypsin in serum does 

 not necessarily imply that no trypsin is present. However, by 

 the methods suggested trypsin can be recovered from serum. 

 Therefore the question arises as to the source of all these fer- 

 ments and the relation which the pancreas bears to them. There 

 are two possibilities, namely : ( 1 ) that the ferments arise from 

 the pancreas, and (2) that they arise from the tissues and that 

 the pancreas serves as an organ of excretion. This phase of the 

 subject will be taken up at another time. 



