1905.] B. lactis aerogenes on Glucose and Mannitol. 403 



is likewise converted into diacetyl by oxidation with bromine in the light, 

 it is important to notice that the glycol used for conversion into diacetyl, as 

 described above, was quite free from any substance capable of reducing 

 Fehling's solution, and yielded a relatively large amount of diacetyl. 



II. Action oj B. lactis acrogcncs on Mannitol. 



A quantitative examination of the products of fermentation of mannitol by 

 B. lactis acrogcncs showed that in this case also the action differed from that 

 produced by B. coli communis, but that the deficit of carbon was only one-half 

 of that found for glucose. This is shown in the following tables : Table III 

 giving the percentages and Table IV the number of carbon atoms per molecule 

 of mannitol represented by the products in two experiments (Cols. 1 and 2). 

 As before, the products obtained by the action of B. coli communis are also 

 given for the sake of comparison (Col. 3) : — 



Table III. 





1. 



2. 



3. 





32-5 



32 



•5 



28 



1 





2-5 



2 



•1 



9 



'5 





8-6 



8 



•6 



18 



•6 





3-2 



2 



•8 



8 



•9 





I 5 



1 



•6 



3 



•o 





35 -5 



35 



•5 



28 



■44 



Carbon dioxide, c.c. per gramme 



180 -3 



180 



■3 



143 



•0 



Hydrogen, c.c. per gramme 



Ratio Ho/CO^ 



138 -3 



143 



•6 



167 



•0 



0-77 







•79 



1 



•18 



Percentage excess of 1-lactic acid 



65-0 



56 



•o 



79 



•o 



Table IV. 





1. 



2 . 



3. 







2-57 



2-57 



2 -22 







0-15 



12 



0-58 







52 



52 



1 13 







0-20 



0-17 



55 







0-06 



-065 ' 



0-12 







1 -47 



1 -47 



1 16 





Total 



4-97 



4 91 



5-76 



H atoms per molecule glucose ... 



2 -26 



1 



2-34 



. 2-7 



