158 TOXINES AND ANTITOXINES. 



PLAGUE TOXINE. 



The plague bacillus also produces soluble poisons which pro- 

 bably belong to the true toxines, although the question is still 

 unsettled. 



The nitrates of quite young cultivations have no poisonous 

 action, as was shown by the concordant results of the German 

 Commission, 1 WERNiCKE, 2 ALBRECHT and GHON. S 



On the other hand, toxic properties are developed in old cul- 

 tivations (even after five days), and increase with their age. 

 The cultures cause death, preceded by emaciation, degenerative 

 changes in the liver, and weakness of the heart's action. The 

 plague toxine has been most thoroughly studied by MARKL. 



MARKL 4 found, first of all, that the cells of bacilli that had 

 been killed by chloroform were very poisonous, but subsequently 

 made use of the filtrates from bouillon cultures instead, which 

 proved fully as poisonous. 



The toxic power was particularly great in the case of old 

 cultures that had been grown at a lower temperature (about 

 20 C.), and it increased up to about the second month, after 

 which it became stationary, and then decreased until eventually 

 the toxine disappeared. Plentiful admission of air to the cultures 

 was most essential. The temperature of incubation had an in- 

 jurious effect upon the toxines. 



The lethal dose of the most active poisons amounted to 0-005 

 to O'Ol c.c. for mice and to about O'l c.c. for rats. 



In the case of these animals the poisoning proceeded rapidly, 

 with symptoms of collapse, but without any anatomical altera- 

 tion except fatty degeneration of the liver; with rabbits and 

 guinea-pigs, however, it only acted in this way when very large 

 doses had been given, and otherwise its action was more pro- 

 tracted, extending over several weeks. Occasionally a splenic 

 tumour and pigmentary atrophy of the liver were produced. In 

 the case of a cat he observed, in addition to marasmus, loss of 

 hair and wide-spread necroses of the skin. In guinea-pigs it pro- 

 duced rigor and extreme lowering of the temperature (25 C.). 



1<< Bericht der dentschen Pest-Comm.," Arb. Kaiserl. Ges. Ami., xvi., 

 1899. 



2 Wernicke, " Ueb. Immun. Vers. b. d. Beulenpest," Centralbl. f. Bah., 

 xxiv., 1894. 



3 Albrecht and Ghon, "Bakt. Unters. itb. d. Pestbac.," Wiener A kad., 

 Ixvi., 1898. 



4 Markl, "Beitrag z. Kenntnis der Pesttoxine," Centralbl. f. Bakt., 

 xxiv., Nos. 18-20 (Bibliography), 1898; id., " Weit. Unters. iib. Pest- 

 toxine," Zeit.f. ffyg., xxxvii.,401, 1901. 



