ANAPHYLAXIS 237 



strates the existence of an antibody in the serum of the sensitive 

 animal ; this antibody has been transferred to the other animal 

 just as the diphtheria antitoxin of the horse can transfer passive 

 immunity to man. 



Passive anaphylaxis can be produced particularly well by 

 injecting the serum of an anaphy lactic rabbit into a normal 

 guinea-pig. Passive transference has also been produced in the 

 case of Richet's poisons. It is therefore a general fact, although 

 experiments of transference between animals of the same species 

 do not always succeed. 



From these fundamental experiments there have proceeded 

 several sets of researches ; especially with the poisons and with 

 serum considerable advances have been made. It is not at all 

 certain in spite of their manifest similarities that the laws of 

 anaphylaxis against poisons and serum (or other non-toxic pro- 

 tein) are really entirely the same. There is always this differ- 

 ence, that in the one case it is a question of substances 

 manifestly toxic to the normal body, whereas in the other the 

 substances are such that the healthy animal shows no visible 

 reaction. 



For the practical point of view, these researches, both 

 on the poisons and on the sera (because of serotherapy), are 

 of obvious value; there is an actual disease to prevent or 

 cure. 



It does not seem as if the anaphylaxis to egg-white should 

 interest us to the same extent. We do not take albumen or 

 milk by subcutaneous, intraperitoneal, or intravenous injections. 

 If, as we know already, our body tends to resist the introduc- 

 tion of foreign albumens, we have a digestive tube which trans- 

 forms these into our own specific protein ; that is perhaps why 

 so few examples exist hitherto of anaphylaxis acquired by taking 

 food. Further, it is probable that we are much more exposed 

 to the cumulative action of toxic bodies, e.g., the phenols of the 

 digestive tube, than to an anaphylaxis to the proteins of the ox 

 or of the fowl. But the digestive tube may occasionally be 

 defective as a defensive agent. 



Poisons also may be absorbed by other routes, such as the 



