86 



LECTURES ON IMMUNITY 



strate plays the same role as that of the enzyme or as the 

 time, which is also probable on the theoretical grounds. 

 The products from a culture of Bacillus pyocyaneus 

 exert a liquefying action on thymolgelatin, just as do pep- 

 sin or trypsin. This action was investigated by Madsen 

 and Walbum. It was found, as for pepsin and trypsin, 

 that the time necessary for liquefying the gelatin to the 

 stated degree is inversely proportional to the quantity of cul- 

 ture employed. The bouillon in which the B. pyocyaneus 

 had been cultivated for two weeks was filtered through a 

 Chamberland filter and a certain quantity (q c.c.) added to 

 2 c.c. of 7 per cent thymolgelatin and (2 q) c.c. of i per 

 cent NaCl solution. The experiments were done at 34.5 C. 

 DIGESTION OF THYMOLGELATIN BY MEANS OF PYOCYANEUS CULTURE 



Madsen and Walbum have investigated the destruction 

 of coli-agglutinin by means of trypsin at 35. 6 C. The 

 strength of the agglutinin was determined by means of its 

 agglutinating power. The observed quantity, q, is that 

 quantity of agglutinin which must be added to a sus- 

 pension of Bacillus coli to obtain a given agglutination 

 in a given time. These values are tabulated below. The 

 strength 5 is the inverse value of q. The reaction is 



