414 INFECTION AND RESISTANCE 



toxic nature of the bacteria or their extracts, it is important to note 

 that Kraus and Doerr and later Kraus and Admiradzibi succeeded 

 in well-controlled experiments in transferring bacterial anaphylaxis 

 "passively" with the serum of previously sensitized animals not 

 only of the same, but of other species (rabbit serum to guinea pigs). 

 These experiments add the final link to the chain of complete analogy 

 between bacterial and serum anaphylaxis. 



This analogy was partly established and, in its completeness, 

 clearly foreseen, when Friedemann's work upon the poisons produced 

 from cells by hemolytic sera, and Friedberger's similar work upon 

 serum precipitates, turned the trend of anaphylactic experimentation 

 into new channels. 



It will be remembered that, before this time, the toxic action of 

 most bacteria (exclusive of "true toxin" producers like diphtheria 

 and tetanus bacilli) had, since Pfeiffer, been attributed to the libera- 

 tion of preformed "endotoxins" from the bacterial body during the 

 process of lysis. 



This idea is fundamental to the opinion of hypersusceptibility 

 expressed by Wolff-Eisner 7 as early as 1904. 



The underlying concept of these ideas is really a morphological 

 one in which the "endotoxin" is regarded as something present in the 

 antigen which is set free by disintegration of the cell. In applying 

 this to serum anaphylaxis Wolff-Eisner 8 preserves this morphological 

 simile in that he speaks of the dissolved protein antigen (serum, 

 etc.) as "nur scheinbar gelost" and "dass es erst durch die Lysine 

 wirklich resorbierbar wird." 



Indeed the sudden liberation of endotoxins by immune sera had 

 been regarded by Pfeiffer and others as the cause of the rapid death 

 often ensuing in immunized guinea pigs when more than a definite 

 maximum of cholera spirilla or other organisms was injected. In 

 all these opinions the basic conception was that certain bacteria con- 

 tained a characteristic preformed poison (endotoxin) upon the 

 pharmacological properties of which the peculiar symptoms caused 

 by each organism depended. 



The earliest unambiguous statements of a conception differing 

 from this original view of the nature of bacterial endotoxins, and 

 approaching the later conceptions of Friedberger, are found, we 

 believe, in the work of Vaughan. 9 In an article by him, published in 

 1908, Vaughan, after describing the incubation time occurring in 

 man and animals after inoculation with typhoid bacilli, says : "The 

 sickness begins when the animal body becomes sensitized and begins 

 to split up the bacilli." By "splitting up" he means here, as in his 



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



8 Wolff- Eisner. "Handbuch der Serum Therapie," p. 24, Lehmanns, 

 Miinchen, 1910. 



9 Vaughan. A m. Jour, of Med. Sci., Sept., 1908. 



