70 FORMATION OF DEFENSIVE FERMENTS 



the harmonious proteins of the plasma are not 

 attacked by the ferments which circulate in the 

 blood. 



Finally, the question may be raised, why the 

 decomposition of parenterally introduced proteins 

 and peptones cannot be followed up directly, by 

 observations on the rotating power of the plasma, 

 without the addition of proteins or peptones. If the 

 appearance of proteo- and peptolytic ferments in the 

 plasma has the object of undertaking the decom- 

 position of the substrates introduced into it, then we 

 ought to be able to follow up the digestion the 

 decomposition in. the plasma itself. As a matter 

 of fact it has been found possible to demonstrate, by 

 means of intravenous introduction of large quantities 

 of proteins and peptones, after the animals have 

 been prepared by previous injections, that, when the 

 blood is withdrawn immediately, not only has an 

 alteration taken place in the original rotation of 

 the plasma, to which nothing has been added, but 

 also that peptones may be found in the outer 

 fluid in the dialysation test. That this demon- 

 stration does not generally succeed i.e., that 

 the decomposition of the substances that are out of 

 harmony with the body cannot be followed up by 

 means of observations on the plasma alone, without 

 the addition of substrates depends primarily upon 

 the fact, that the injected substances suddenly become 



