1905.] 



B. lactis aerogenes on Glucose and Mannitol. 



401 



no other acids had been formed, and search was therefore made for com- 

 pounds of a different type. It was previously suggested that the deficiency 

 of carbon observed in the fermentation produced by B. coli communis, 

 amounting to only 0*25 to 0"9 of an atomic proportion of carbon, might 

 possibly be due to the presence of reduction products of sugar, and com- 

 pounds of this kind were therefore sought. 



It was found that when the neutral liquid, containing the products of 

 fermentation along with peptone, was evaporated to dryness at 55° under 

 diminished pressure and extracted with alcohol, a solution was obtained 

 which yielded on fractionation a colourless liquid boiling at 181° to 

 183° (corr.) at 760 mm. pressure. The yield was very small, only amounting 

 to about 1 gramme per litre of medium containing 20 grammes of glucose, 

 but it was found possible to increase the yield by employing a medium 

 containing 5 per cent, of glucose, and in this way 8 grammes of the new- 

 substance, containing 52'8 per cent, of carbon, were obtained per litre of 

 medium containing 50 grammes of sugar. This only accounts for about 

 two-thirds of the missing carbon, and a rough estimate of the amount 

 lost during the process of distillation and extraction was, therefore, made 

 by dissolving 8 grammes of the material in 500 c.c. of a medium containing 

 5 grammes of Witte peptone, 6 grammes of calcium lactate and 6'5 grammes 

 of alcohol and then extracting it in the manner described above. Only 

 5 - 2 grammes were recovered, the loss per 500 c.c. being therefore about 

 2 - 8 grammes and the loss per litre about 5 - 6 grammes. This brings the 

 Total amount produced from 50 grammes of glucose to about 13 - 6 grammes, 

 slightly in excess of that required. It is hoped that the actual yield may 

 be increased by a careful fractionation of the fermentation products. 



The new product is apparently a mixture, and it has not yet been found 

 possible to separate and identify all the components, so that the following 

 must be taken as only a preliminary account of the substance. 



It boils at 181° to 183° (corr.), and solidifies in the cold to a transparent 

 mass which melts indefinitely at about 28°. It is optically active, the value 

 for [a] D for different preparations varying from - 46 to 071. The com- 

 position of the substance dried by quicklime is approximately that of 

 a butyleneglycol, but the percentage of carbon is about 0'6 too low. 

 It does not reduce Fehlino's solution either in the cold or on heating. 

 That this substance contains a large proportion of 2 : 3-butyleneglycol. 

 CH 3 .CH(OH).CH(OH).CH 3 , is shown by the following facts :— 



1. "When the liquid is heated with phenylisocyanate dissolved in anhydrous 

 ether, combination occurs and a mixture of urethanes is produced. The 

 fraction of these which is least soluble in alcohol comprises about 90 per cent. 



2 G 2 



