502 Mr. J. Thompson. The Chemical Action of [Nov. 22, 



Glucose. 

 Table II. — Carbon Atoms. 





B. cloaex. 



B lactis 



B. coli. 









aerogenes. 







1. 



2. 



3. 



4. 



Alcohol 



1 -30 



1 -03 



1-34 



1 -01 



Acetic acid 



0-07 



0-18 



0-31 



113 



Lactic acid 



0-12 





-33 



1 -91 



Succinic acid 



0-12 



0-11 



0-15 



0-32 



Formic acid 



0-17 



0-13 



0-04 



o-oo 



Carbon dioxide 



1-71 



1 -68 



1 -60 



0-74 



Total 



3-49 



3-79 



3-77 



5-11 



Hydrogen, atoms per molecule 



1 -04 



0-90 



1-33 



1-77 



H 2 /C0 2 = 1:1, but this result does not represent the actual ratio of the 

 gases produced, owing to the solubility of the carbon dioxide in the liquid 

 medium contained in the ordinary fermentation tubes which he employed. 

 This source of error has been obviated, as already pointed out, by collecting 

 the gases over mercury in an evacuated flask. Formic acid was found in 

 the products obtained from B. cloacm in far greater amount than in those 

 from B. lactis aerogenes, while those given by B. coli are usually almost free 

 from this substance. It is, however, probable that at least a portion of 

 the carbon dioxide is derived from the decomposition of formate primarily 

 formed as an intermediate product. A very marked difference in the 

 relative proportions of alcohol and acetic acid produced by the three 

 organisms will be noticed. While the molecular ratio alcohol/acetic acid 

 for B. coli communis* is 1, and for B. lactis aerogenes (average of three 

 determinations) = 4, that for B. cloaca was found in two experiments to be 

 18 and 6. The large difference between these results is due to the fact 

 that only a very small amount of acetic acid is produced, and a small absolute 

 difference in this produces a large change in the ratio. Succinic acid is 

 produced by B. cloacce in rather smaller amount than by B. lactis aerogenes, 

 and in less than half the quantity given by B. coli communis. The amount 

 of alcohol is approximately equal to that given by B. lactis aerogenes. A 

 considerable deficiency of carbon in the fermentation of glucose by B. cloacce 

 was found, and, remembering the very similar biological characters of 

 B. cloacce and B. lactis aerogenes, butylene glycol was sought for. 



* Harden, ' Journ. Hygiene,' 1905, vol. 5, p. 488. 



