BACTERIAL POISONS. 



69 



acid and ferrocyanide of potassium cause a precipitate, 

 although the diphtheria toxine does not give the last 

 reaction. On the evidence of these tests it is held that 

 the toxines of cholera and diphtheria are proteid bodies 

 like peptones or albumoses, and that they are syntheti- 

 cally produced by the micro-organisms. The latter part of 

 this conclusion is probably correct, and is of great interest, 

 but a far more extended chemical investigation is necessary 

 before the proteid nature of these toxic substances can be 

 considered proved. 



In a subsequent communication 1 Ouchinsky gives the 

 results of a renewed study of the poisons produced by 

 the micro-organisms of typhoid, cholera, diphtheria, and 

 tetanus, when cultivated upon a fluid of the following- 

 composition : — 



The tetanus bacillus thrives on this fluid when 1-2 

 parts of sugar is added, and the access of oxygen is pre- 

 vented by an alkaline solution of pyrogallic acid. The 

 growth passes through the same stages as is observed in 

 bouillon media, but the bacilli are somewhat thinner than 

 normal. The filtered cultures show a marked toxic power ; 

 '6-'8 ccm. sufficed to kill rabbits of a moderate weight. The 

 poison in the filtrate is destroyed on the addition of alcohol, 

 or when this is concentrated in a vacuum at ^o°-t,6°, this 

 effect being most obvious when the operation is done in 

 daylight. The toxine of the filtrate can be obtained by 

 precipitation with calcium phosphate, a method which was 



1 Ouchinsky, Centralblatt f. Bacteriologie u. Parasiten-kunde, Sept., 



1893. 



