THE MICROBIAL TOXINS. 79 



tive reaction of the cells, which makes these resist- 

 ant to the poison. As in the case of the other 

 toxins, the quantity of antitoxin necessary to 

 protect an organism is so much greater the later 

 the treatment is applied. 



Mallein (Toxin of Glanders). Among the soluble 

 products secreted in the culture media by the 

 glanders bacilli, there are found true toxins to 

 which are ascribed certain symptoms of glanders 

 infection. These toxins have been isolated and 

 designated by the name mallein. First prepared 

 by Helman and Kalmino, mallein was later on 

 specially studied by Roux and Nocard, and, in 

 consequence of the researches of the last-men- 

 tioned scientist, it has acquired great importance.* 

 It is obtained by sterilizing at 110 C. cultures of 

 the glanders bacillus made with mutton bouillon 

 with the addition of salt, glycerin, and peptones. 

 To isolate the toxin the culture bouillon is first 

 sterilized by heating for half an hour in an auto- 

 clave at 100 C. It is then filtered, concentrated 

 to one-tenth its volume on a water-bath, and fil- 

 tered through a Chardin filter. The mallein is 

 thus obtained in the form of a brown syrupy 

 liquid containing half its weight of glycerin. 



This solution keeps well when kept from air, 

 light, and heat. In practice it is employed in lo-per 



* NOCARD: Le$ Maladies microbiennes des animaux, Paris, 



