400 Dr. Harden and Mr. Walpole. Chemical Action of [Dec. 5, 



fermentation of glucose by B. coli communis are added (Col. 4) for tlie sake 

 of_coniparison : — 



Table I. 





1. 



2. 



3. 



4. 





17 -1 



16 -4 



18 -2 



12 -85 





5 1 



4-2 



8-6 



18 -84 





5 5 



4-7 



9 1 



3190 



Succinic acid 



2-4 



3-1 



4-5 



5-20 





1-0 



0-75 



1-7 



o-o 



Carbon dioxide 



38 -0 





35 -2 



18 -09 



Carbon dioxide, c.c. per gramme 



198 -3 





178 -5 



91 -8 





82 -4 





92 -4 



110 



Eatio Ho/C0 2 



0-42 





0-52 



1 -19 



Percentage excess of 1 -lactic 



50 -0 



66 -0 



86 -0 



Not 



acid 









determined 



Table II. 





1. 



2. 



3. 



4. 





1-34 



1-28 



1-43 



1-01 





0-31 



0-25 



0-52 



1 13 



Lactic acid 



33 



0-28 



0-55 



1-91 





0-15 



0-19 



0-27 



0-32 



Formic acid 



0-04 



0-02 



0-07 



o-oo 



Carbon dioxide 



1 -60 





1-44 



0-74 



Total 



Hydrogen, atoms per molecule ... 



3-77 





4-28 



5-11 



1-33 





1-50 



1-77 



It will be observed that the ratio of hydrogen to carbon dioxide by volume 

 is about - 5 to 1, whilst these gases are produced by B. coli communis 

 in approximately equal volumes. Theobald Smith,* using an ordinary 

 fermentation tube, gives the characteristic ratio for B. coli communis as 

 H 2 /C0 2 =2:1 and for B. lactis aerogcnes H 2 /C0 2 =1:1. This difference 

 is due to the solubility of the carbon dioxide in the liquid medium, and 

 it must be remembered that while Smith's ratios give a perfectly satisfactory 

 working test for the discrimination of the organisms, they do not represent 

 the actual volumes or ratios of the gases produced. 



Further examination of the fermentation products revealed the fact that 



* Loc. cit. 



