390 INFECTION AND RESISTANCE 



the animal body of an antigen with its specific antibody. In "active" 

 anaphylaxis the antibodies are present as the reaction to a preceding 

 antigen injection. In the "passive" condition they were conveyed 

 with the injected antiserum. 



We are now prepared to follcfw individually the development of 

 those theories in which the anaphylactic mechanism was looked upon 

 purely as the result of the union of an antigen with its antibody. 



The conception which gradually grew out of the antigen-antibody 

 mechanism of anaphylaxis was the following: When a specific an- 

 tigen meets its antibody the reaction between them gives rise to a 

 toxic product, and this causes the characteristic symptoms. A simi- 

 lar idea, it will be remembered, is found in the original endotoxin 

 theory of Pfeiffer. According to this, the action of the specific 

 lysin liberated from bacteria a preformed poison, the endotoxin. In 

 1902 Weichhardt, 14 bearing this conception in mind, subjected 

 syncytial protein of rabbit placenta to the action of specific antisera 

 and obtained substances toxic for normal rabbits. 



This work was done long before the days of anaphylaxis studies, 

 and the results were interpreted in keeping with Pfeiffer's theory. 

 However, as Weichhardt himself now claims, it is not unlikely that 

 he was dealing with a phenomenon analogous to the ones we are now 

 discussing. A similar opinion of the production of toxic substances 

 by specific cytolysis was expressed by Wolff-Eisner 15 in 1904. 



Probably the most important of the earlier investigations along 

 these lines, at least in its direct bearing on anaphylaxis, was the 

 work of Vaughan and Wheeler, 16 published in 1907. 



In its general significance this work ranks among the most im- 

 portant contributions to our understanding of hyper susceptibility, 17 

 though the theoretical deductions made from it have had to be sub- 

 jected to considerable alteration. Their conception of anaphylaxis 

 takes root in the earlier investigations of Vaughan 18 and his pupils 

 upon the extraction of a poisonous group from the protein molecule. 



Vaughan and Wheeler 19 , 20 believe that the sensitizing and the 

 toxogenic properties of the anaphylactic antigens are in truth con- 

 tained within the self-same proteid molecule; but can be chemically 

 separated from each other. They have been able to split egg al- 

 bumen and other proteids by treatment with absolute alcohol (con- 



14 Weichhardt. Deutsche med. Woch., 1902, p. 624. 



15 Wolff- Eisner. Centralbl. f. Bakt., Vol. 37, 1904. 



16 Vaughan and Wheeler. Jour. Inf. Dis., Vol. 4, 1907. 



17 This work also contains the germ of the more recent ideas upon the 

 nature of toxemia in infectious disease, advanced more particularly by 

 Friedberger. This will be considered in detail in the next chapter. 



18 Vaughan. Transact. Ass'n Am. Phys., Vol. 16, 1901; Jour. A. M. A., 

 Vol. 36, 1901; Am. Med., 1901; Jour. A. M. A., Vol. 43, 1904. 



19 V. C. Vaughan, Jr. Jour. A. M. A., Vol. 44, 1905, p. 1340. 



20 V. C. Vaughan, Jr. Boston Med. and Surg. Jour., Vol. 155, 1906. 



