OTHER REACTIONS 199 



terest has been aroused by the discovery that in 

 certain diseases, especially cancer, the antitrypsin 

 content of the patient's serum is markedly in- 

 creased. In cancer this increase is noted in about 

 90 per cent of the cases. The antiferment action 

 is not entirely specific, but extends to other pro- 

 teolytic ferments, and particularly to the ferment 

 of leucocytes. At the present time, therefore, a 

 marked increase in the antitryptic power of a 

 patient's serum is taken to indicate an increased 

 parenteral 1 destruction of proteid in the body. 2 

 The original method of demonstrating the presence 

 of this antitrypsin was by placing drops of pro- 

 teolytic ferment (trypsin) on the surface of a plate 

 of Loeffler's serum, and causing the development of 

 small concavities owing to the digestion of the 

 medium. The addition of inhibiting serum to the 

 drops was able to prevent the formation of the 

 concavities. A more convenient and accurate 

 method is the one developed by v. Bergmann and 

 Meyer. This depends on the digestion of a per- 

 fectly-clear solution of casein. If all the casein has 

 been digested, the addition of acid is obviously 

 unable to precipitate any casein from solution. 

 On the other hand, if the acid causes clouding or 

 precipitation, it follows that all the casein was not 



1 Other than intestinal. 



1 See the excellent digest of the work on this subject in Jahres- 

 bericht der Immunitatsforschung, Bd. V, 1909, Abteilung I, page 

 58- 



