PREFACE 



IX 



tolerates a large quantity of the substance which, 

 previously, would have killed it in the smallest doses. 

 Whilst sensitisation is only acquired after an in- 

 terval, desensitisation is, so to speak, instantaneous, 

 and constitutes anti-anaphylaxis, which is as specific 

 as anaphylaxis itself. 



Having specified these characteristics of anaphy- 

 laxis. Dr. Besredka goes on to discard all those ex- 

 periments in which preliminary preparation and 

 specificity are lacking, as they have nothing to do 

 with true anaphylaxis. Indeed, the fact of a guinea- 

 pig dying speedily following the injection of some 

 substance intravenously, after having exhibited con- 

 vulsive movements and arrest of respiration, does 

 not authorise us to cite the case as one of anaph}^- 

 laxis. The almost sudden death of guinea-pigs which 

 are injected intravenously with serum shaken up with 

 kaolin or brought into contact with agar, does not 

 constitute a death due to anaphylaxis. It is due to 

 circulatory trouble, caused, possibly, by the coagu- 

 lation of blood in the small vessels, but in these cases 

 we do not find the characteristics of anaphylaxis. In 

 order to avoid the mishaps that follow intravenous 

 injection, Dr. Besredka prefers to use intrathecal 

 injection. This test has led him to eUminate from 

 the signs of anaphylaxis the anaphylotoxins of Fried- 

 berger, alarming in their effects if introduced intra- 

 venously, and harmless when they are made to pene- 

 trate the nervous centres. 



Having thus. very wisely narrowed the limits of 

 the domain of anaphylaxis. Dr. Besredka arrives at 

 the more interesting point of his subject — namely, 

 that of ascertaining the mechanism of the phenomena 

 of anaphylaxis. 



Everyone admits that after the preparative injec- 

 tion and during the incubation period a fresh sub- 

 stance is formed in the organism — namely, a specific 



