THE PARENTERAL INTRODUCTION OF PROTEINS 365 



of course, be understood that the non-specific proteolytic 

 ferments are capable of digesting a more or less extended 

 group of proteins, but with this ferment the digestive process 

 proceeds slowly, and it is not supposable that all proteins 

 would be digested by it. 



From the second set of sensitized guinea-pigs Abder- 

 halden took the serum and dialysed it by itself, the purpose 

 being to see if, while in the sensitized state, the blood-serum 

 contains any diffusible biuret body. The serum from 

 six sensitized guinea-pigs was tested in this way, and only 

 in one instance did the dialysate respond to the biuret 

 test. On the eighteenth day after sensitization the remaining 

 guinea-pigs (6) were reinjected and blood was taken five, 

 fifteen, thirty, forty-five, sixty, and ninety minutes after 

 the reinjection. The serum obtained from the samples 

 of blood was dialyzed and the dialysate subjected to the 

 biuret test. The samples taken five and fifteen minutes 

 after reinjection failed to yield dialysates which responded 

 to the biuret test, while the remaining four did. This 

 experiment demonstrates that at the very moment when 

 anaphylactic shock is being developed, peptone-like bodies 

 are being formed in the blood. It is probable that the 

 specific digestion of the protein begins at the very moment 

 that the reinjection is made, but that further time is neces- 

 sary for the digestive product to accumulate in a few cubic 

 centimeters of blood serum in recognizable amount. The 

 biuret test is not a highly delicate means of recognizing 

 proteins. 



H. Pfeiffer and Jarisch 1 have repeated diffusion experi- 

 ments. The method of procedure may be briefly described 

 as follows: Guinea-pigs are sensitized with horse serum, 

 and after varying intervals they are bled and serum obtained. 

 The serum of the sensitized animals is mixed with varying 

 amounts of horse serum, and the mixture incubated in 

 small dialyzers. If digestion takes place, peptone-like 

 products are formed, diffuse through the membrane, and 



1 Zeitsch. f. Immunitatsforschung, 1912, xvi, 38. 



