THE MICROBIAL TOXINS. 77 



stances * highly toxic alkaloidal bases (ptomaines, 

 tetanin, tetanotoxin, etc.), and a true toxin, pos- 

 sessing diastatic properties, and of almost incredi- 

 ble toxic power. 



This toxin had already been isolated by Kitasato. 

 It is a toxalbumin, and is very sensitive to the 

 action of heat. A temperature of 65 C., main- 

 tained for 30 minutes, renders it quite inactive; 

 and it becomes oxidized and is destroyed by the 

 action of the air in the presence of light. 



Brieger and Boer,f by precipitating with zinc 

 chloride the filtered culture bouillon, obtained 

 a pure, amorphous tetanus toxin, which they also 

 considered as a toxalbumin, and which possesses 

 exceedingly toxic properties. 



If a precipitate be caused to form in these toxic 

 solutions, as, for instance, a precipitate of cal- 

 cium phosphate, this carries down with it all the 

 toxin present in the liquid. 0.0005 & m - f this 

 precipitate is surely fatal to a guinea-pig. 



Dozon and Cournemont have observed that 

 even in doses of 300 to 400 Gm. of the filtered cul- 

 ture liquid, this toxin is not immediately toxic 

 to a horse, but kills the animal only after a period 

 of incubation of at least twenty-four hours. The 

 blood of such an animal, however, is immediately 



* Annal. Instil. Pasteur, V, 15. 



f Deutsche Med. Wochenschr., No. 49, Dec. 3, 1896. 



