356 Pure Fermentation of Mannite and Glycerin. [June 20, 



Remarks. 



(1.) Both mannitol and glycerol are fermented by this organism, 

 with production of essentially the same substances, viz., ethyl alcohol 

 and acetic acid, together with smaller quantities of formic and suc- 

 cinic acids. 



The proportion of formic acid in both fermentations appears to be 

 formed at the expense of the acetic acid, inasmuch as in all cases the 

 amount of acetic acid found varied inversely as the proportion of 

 formic acid. The proportion of succinic acid, although in both cases 

 very small, was distinctly greater in the glycerol than in the mannitol 

 fermentations. 



(2.) The proportion of alcohol to acetic acid in the mannitol fer- 

 mentations is constant, viz., as 1*63 : 1, which corresponds to the 

 molecular proportions. 



2C 2 H 5 -OH : CH 3 -COOH = 1-53 

 (2x46) (60) 



(3.) Excluding the first glycerol fermentation, in which the alcohol 

 found was doubtless too small, the proportion of alcohol to acetic 

 acid is as 2' 11 : 1, corresponding to the molecular proportions, 



3C 2 H 5 -OH : CH 3 -COOH = 2-30 

 (3 x 46) (60) 



(4.) In all the fermentations the decomposition was only an incom- 

 plete one, a considerable part of the mannitol, and especially of the 

 glycerol, being in each case recoverable after the fermentation was 

 finished. We propose subsequently to investigate the cause of this 

 limitation. 



(5.) In the mannitol fermentation it is impossible to determine 

 whether the succinic acid is formed by a process of synthesis or 

 analysis, but in the fermentation of glycerol it obviously has a 

 synthetical origin. 



(6.) In addition to ethyl alcohol, there appears to be also a small 

 proportion of some higher alcohol produced, for in the alcoholic 

 distillation the distillate was at first somewhat turbid, but became 

 clear again when a larger quantity had collected.. 



(7.) We have introduced pure cultivations of the same bacillus 

 into solutions of a number of different substances likely to undergo 

 fermentation. The bacillus, as already mentioned, ferments glucose 

 vigorously, it also more slowly ferments cane-sugar, milk-sugar, 

 starch, and calcium glycerate ; the products of these fermentations 

 are being further investigated by one of us. On the other hand, we 

 have been unable to cause it to ferment solutions of dulcite, erythrite, 

 ethylene glycol, calcium lactate, tartrate, citrate, or glycollate. 



