ADDITIONAL EXAMPLES OF ANAPHYLAXIS 83 



the first researches of Charles Richet, henceforth to 

 become classical, were devoted. 



Important researches by the same author were 

 next carried out on crepitin^ which is the toxin of 

 Hura crepitans. This is a nerve poison with an 

 extremely slow action which acts on the secretion 

 and vasomotor innervation of the stomach and 

 intestines. In the case of the dog a second injection 

 of crepitin sets up symptoms of anaphylaxis com- 

 parable in every respect with those observed with 

 actino- or mytilo-congestin. 



We have succeeded with crepitin better than with 

 any other substance in realising what Charles Richet 

 calls anaphylaxis in vitro. By mixing this poison 

 with serum derived from a sensitised dog, and by 

 next injecting this mixture into a fresh dog, he 

 succeeded in then and there producing anaphylactic 

 shock. It is in this experiment that Charles Richet 

 demonstrates the newly formed poison — apotoxin — 

 which in his opinion is the cause of anaphylaxis. We 

 shall return to this later, when discussing the various 

 theories of anaphylaxis. 



Anaphylaxis experiments have been conducted 

 with the fluid of hydatid cysts, the fluid of cosnurus, 

 extract of mussels, of rice, of kidney beans, of wheat, 

 of maize, etc. 



Karasawa^ made a study of vegetable proteins in 

 this connexion. He triturated wheat, kidney beans, 

 and rice finely, and prepared from them watery 

 extracts, with which he sensitised guinea-pigs. Ten 

 to thirty days later the animals were tested, either 

 with the extract which had been used for sensitisa- 

 tion or with some other extract. 



These experiments shewed that the substances in 

 question were capable of giving rise to the same 



1 Annates de I'lnstitut Pasteur, xxiii., p. 745, 1909. 



2 Zeitschr. /. Immunitdtsf., I. Orig., v., p. 509, 1910. 



