TOXIC OR EXCITING INJECTION 35 



pigs die the day after the operation independently 

 of their anaphylactic state as a result of local infection. 

 In all anaphylaxis experiments we therefore recom- 

 mend the employment of milk heated to ioo° C. This 

 temperature does not perceptibly diminish the toxicity 

 of the milk. 



It should be recollected that the reverse is the case 

 with sera; they lose all their toxic action at a 

 temperature of 100** C. even when they are not 

 coagulated. 



Milk when heated to 100° and even to 120° C. for 

 a quarter of an hour kills a hypersensitive guinea-pig 

 in a dose of 0-25 c.c, and even o-i c.c. The persist- 

 ence of this toxicity is clearly due to the fact that the 

 milk remains perfectly fluid even at high temperatures . 

 Above 120° C. the milk, while apparently remaining 

 quite fluid, loses its toxicity so much that when heated 

 to 130° C. for fifteen minutes, although slightly toxic 

 {i.e., producing cough, hurried respiration, tendency 

 to prostration), it no longer kills when injected in a 

 dose of 0-25 C.C. When the milk is heated to 135° to 

 140° C. it becomes gelatinous, and in that state of 

 semi-coagulation it is not toxic at all. 



It is just as well to add that in the normal guinea- 

 pig — that is to say, in one not previously sensitised — 

 the intracerebral injection of milk never gives rise to 

 the slightest trouble. 



Experiments have shown us that the toxicity of 

 milk is specific without, however, its being as strictly 

 so as in the case of serum. Thus we verified the fact 

 that guinea-pigs sensitised with cow's milk did not 

 react to the intracerebral injection (0-25 c.c.) of human 

 milk; on the other hand, they reacted readily to 

 goat's milk, and succumbed to the effect of the in- 

 jection in a few minutes. The specificity of lactic 

 anaphylaxis is therefore not absolute; it is of less 

 degree than serum anaphylaxis. 



