THE WONDER OF LIFE 503 



than an obscure anomaly (always a clue to be followed 

 up), tiU Richet tackled it in 1902, and coined for it the 

 name Anaphylaxis — a companion word to prophylaxis, 

 which means protection against a disease. (See Richet's 

 L'Anaphyktxie, Paris, 1912.) 



Let us follow Professor Richet's work. One of his early 

 experiments was with the poison in the stinging cells 

 of the sea-anemone's tentacles — a poison which we can feel 

 if we have the courage to put the tip of our tongue to the 

 sea-anemone's mouth. Our finger will not suffice, for the 

 poison-bathed lassoes of the stinging cells are not suffi- 

 ciently strong to penetrate the skin of our hands. Richet 

 made an extract by soaking the tentacles of Actinia in 

 glycerine, and he injected the poison thus obtained 

 into the veins of a dog. He found that a rather large dose 

 was required to cause death, but what came to him as a 

 surprise was the discovery that a dog which had fully 

 recovered from treatment and was subjected to a fresh injec- 

 tion a month afterwards, succumbed to a dose of about one- 

 twentieth the original strength. It might be suggested 

 that the poison was cumulative, and that the second dose 

 was the last straw that broke the camel's back, but the 

 improbability of this was evidenced by the time that had 

 elapsed since the previous injection and by the smaUness 

 of the second dose. The only possible conclusion from 

 this and other experiments was, that the first dose brings 

 about a peculiar physiological condition which makes the 

 organism hyper-sensitive to subsequent doses. 



A further step was taken in 1903, when M. Arthus 

 showed that the anaphylactic condition could be induced 

 by a substance, such as blood-serum, which is not in itself 

 toxic. A rabbit, which had been injected with a dose of 



