A NAPH YLAXIS 143 



laxis, and that they even gave a sufficiently clear explanation 

 of its mechanism. 



In spite of all the foregoing experiments it was as a dis- 

 covery of a new phenomenon that most biologists regarded 

 anaphylaxis when introduced by Charles Richet and Portier 

 in 1902. 



These scientists discovered that an albuminoid substance 

 called actino-congestion, extracted from the tentacles of 

 sea-anemones, when injected into the veins of dogs, was 

 toxic at certain doses, and innocuous at feebler doses. Con- 

 gestion should therefore have been regarded as a toxin, and 

 behave as such: The injection of a non-lethal dose into an 

 animal should have vaccinated it against a later injection 

 of a dose fatal for the control animals. 



To their great surprise, the experimenters had to record 

 a result which was exactly the contrary. 



"The characteristic experiment," writes Charles Richet, 1 

 "the one which showed the phenomenon in all its indis- 

 putable clearness, was made on the dog Neptune. This was 

 an animal of exceptional strength and health. He first 

 received 0.1 c.c. glycerinated extract of sea-anemone ten- 

 tacles without becoming ill. Twenty-two days later, as he 

 was in excellent health, I injected the same dose of 0.1 c.c. 

 A few seconds after the injection, he became very ill; respira- 

 tion became painful and panting. He could hardly drag 

 himself along, lay down on his side, was seized with diarrhea 

 and bloody vomiting. Sensation disappeared and he died 

 in twenty-five minutes." 



Having thus obtained a reaction contrary to vaccination or 

 prophylaxis, Richet called this phenomenon "anaphylaxis." 



Neither Richet, nor all those who were interested in these 

 experiments, saw anything in common between anaphylaxis 

 and the phenomena described by Hayem, Krauss, Belfanti, 

 Bordet, and others, because it seemed hardly possible to 

 correlate the action of a poison (actinocongestin) with that 

 of blood or serum from animals of allied species which were 

 obviously considered as essentially alimentary substances. 



On the other hand, it was already known that injections 



1 Anaphylaxis, S. F. Alcan, p. 3, 



