PREFACE 



It is rarely that the significance of a discovery is 

 immediately understood, especially if this discovery 

 is unexpected. Such has been the case with ana- 

 phylaxis. In 1902 Charles Richet and Portier dis- 

 covered that a dog that, twelve days previously, had 

 received a harmless dose of actino-congestin, became 

 so sensitive to the effect of this substance that it 

 succumbed in a few minutes to a fresh injection of an 

 amount far less than the dose lethal to another dog. 

 In spite of the fact that the authors laid stress on the 

 very peculiar characteristics of the phenomenon they 

 had just discovered, and that they had marked its 

 novelty by giving it a special name, there were many 

 who only saw in it a striking example of sensitisation 

 in respect of a poison. Charles Richet and Portier, 

 however, viewed the matter in quite a different light, 

 and doubts as to the exceptional nature of the pheno- 

 menon became impossible after Arthus, Otto, and 

 later Rosenau and Anderson had found that a sub- 

 stance as harmless in appearance as horse serum was 

 able to set up fatal anaphylactic symptoms. It was 

 soon recognised that anaphylaxis could be produced 

 by the majority of albuminoid substances, whether 

 of animal or vegetable origin. The subject of ana- 

 phylaxis henceforth assumed an importance of which 

 at first it had not been suspected to be capable. |Its 

 quasi-mysterious character so much stimulated the 

 enthusiasm of workers that memoirs innumerable 



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