24 



were produced through the activity of the cholera spirillum, as 

 may be seen in Table III: 



Tahle III. 



It will also be noted that the faint trace of nitrites aljsorbed from 

 the atmosphere was not sufficient to yield any reaction, when 

 sulphuric acid alone was added, but that the addition of nitrite 

 and sulphuric acid produced a very distinct indol reaction. 



In the dialyzed medium containing 0.01 per cent sodium nitrate, 

 the cholera spirillum almost completely reduces the nitrates to 

 nitrites in twenty-four hours, as shown in Table IV: 



Table IV. 



