186 PRODUCTION OF CARBON DIOXIDE 



It appears therefore that the observed diminution of carbon dioxide 

 production caused by the addition of NaOH to bacterial emulsions 

 cannot be the result of any so called buffer action, but it is a true 

 expression of the effect of an alkaline environment upon the bacteria. 



SUMMARY. 



1. The maximum rate of CO2 production of Bacillus hutyricus was 

 found to be at a pH value of 7; of Bacillus suhtilis at pH 6.8. If the 

 pH value be raised or lowered there is a progressive decrease in the 

 rate of production of CO2. 



2. Spontaneous recovery follows the addition of alkali to either 

 organism, while addition of acid is followed by recovery only upon 

 addition of an equivalent amount of alkali, and is not complete except 

 when the amount of acid is very small. 



