SENSITISING INJECTION 21 



the albuminoid substances that not only did the 

 sensibiligen disappear, but the serum itself also lost 

 its biological characters. 



The anaphylactic state may also be produced with 

 proteins other than those contained in blood-serum- 

 The animal may be sensitised with milk, egg-albu-- 

 men, organic extracts, toxalbumins, bacteria, etc. 



For the present we shall only mention milk and 

 egg-albumen, which exhibit many features in common 

 with sera from the point of view of anaphylaxis. 

 The other substances will form the subject of a 

 special chapter, the more so as their sensitising func- 

 tions have been and are still disputed, because they 

 are not so definite in their results as milk, egg- 

 albumen, or serum. 



Sensitisation with Milk} — Upon injecting unboiled 

 (raw) and boiled cow's milk into guinea-pigs sub- 

 cutaneously, we have noticed that sensitisation by this 

 route has disadvantages which are due to the slow 

 and unequal absorption of the milk. The intra- 

 peritoneal route is better suited — so long, however, as 

 unboiled milk is not used. The latter often causes 

 the animals to become emaciated, and in time may 

 set up a condition of cachexia. Milk heated to 

 1 00° C. for twenty minutes is best for sensitisation. 

 We inject i c.c. intraperitoneally, and for this pur- 

 pose select by preference guinea-pigs weighing 300 

 to 400 grammes. Starting from the sixteenth day — 

 or, with greater certainty still, from the twentieth 

 day — the guinea-pigs, in the majority of cases, 

 acquire a hypersensitiveness to a fresh injection of 

 milk which is quite remarkable . 



The substance in the milk which produces ana- 

 phylaxis in the guinea-pig, or the sensibiligen of the 

 milk, to make use of a term now sanctioned by 

 usage, is thermostable. It withstands a temperature 

 ^ Annates de I'lnstitut Pasteur, 1909. xxiii., p. 166. 



