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UNIVERSITY OF WISCONSIN STUDIES 



the fact that under the conditions used in our work 264 

 cultures from a great variety of sources gave CO../H., ratios 

 varying only from 1.0 to 1.1. The amount of gas, as would 

 be expected, was subject to greater variation, but for a certain 

 type of culture under definite conditions the volume of gas 

 could be predicted with considerable accuracy. The kind of 

 gases formed in the anaerobic fermentation of sugars was 

 limited to carbon dioxide and hydrogen with a very small 

 amount of a residual gas which was undoubtedly nitrogen. 

 The origin of this residual gas is not certain but it obviously 

 has no part in the main fermentation. 



A total of 615 cultures has been subjected to an exact deter- 

 mination of the gas produced in the anaerobic fermentation 

 of dextrose. The results of these determinations are as- 

 sembled in Table I and Fig. 1, and include all of the cultures 

 with the exception of a few from water. 



Fig. I 



In making the frequency polygons shown in Fig. 1, the 

 liquefying and non-liquefying cultures have been separated 

 and the percentages calculated for the two groups separately. 

 The proportion of liquefying cultures was so small that it was 

 necessary to make the calculations in this way. While this 

 distinction may seem to ascribe an undue importance to the 

 liquefaction of gelatin it follows the usual custom and is 

 probably justified. 



