FERMENTATION OF THE FATTY ACIDS. 603 



from glycerine, and was dealing therefore probably with the 

 combination of the two fermentations first mentioned. In all 

 these decompositions of glycerine, with the exception, perhaps, 

 of the fermentation by bacillus Fit zianus, which has been more 

 accurately studied by Buchner, the methods employed do not 

 furnish a sufficient guarantee for a thoroughly pure growth, 

 and the morphological characteristics of the fermenting 

 agents have not been sufficiently attended to, and thus the 

 value of these careful chemical investigations is diminished. 



In the case of erythrite Fitz also found a number of fer- Erythrite. 

 mentations ; one bacterium caused a decomposition in which 

 two molecules of erythrite were split up into one molecule of 

 butyric acid, and one molecule of succinic acid, with a loss of 

 2H 2 and 1 H; another bacterium caused a fermentation 

 with only slight traces of succinic acid. 



Mamiite, in the first place, gives rise to the lactic fermenta- Mannite. 

 tion above mentioned. According to Fitz also, a bacterium 

 causes in a three per cent, solution of mannite the formation 

 of normal butylic alcohol, sethylic alcohol, succinic acid, and 

 lactic acid ; and a club-shaped bacillus obtained from boiled 

 hay infusion furnished aethylic alcohol (26 per cent.), formic 

 acid (5'6 per cent.), and a little succinic acid. 



Dulcite behaves very similarly to the carbo-hydrates as Dulcite. 

 regards the lactic fermentation. According to Fitz, dulcite 

 also gives rise to a fermentation with a little alcohol and 

 much butyric acid. Quercite gives rise to a fermentation 

 with the almost exclusive formation of normal butyric acid. 



(y). Fermentation of the Fatty Acids. 



Numerous acids belonging to the group of fatty bodies Fermentation 

 form a suitable fermentescible material when they are cids ty 

 given to bacteria in the form of neutral salts. The lime 

 salt of these acids seems to be the most suitable, and 

 with it almost all the experiments on fermentation have 

 been made. The following are capable of undergoing 

 fermentation: formic acid (HCOOH), acetic acid (CH 3 , 

 COOH); further, a number of oxy-acids, namely: 

 lactic acid (C 2 H 4 , OH, COOH), glycerinic acid (C 2 H 3 , 

 (OH) 2 , COOH), malic acid (C,H 3 , OH, (COOH) 2 ), tar- 

 taric acid (C 2 H 2 , (OH) 2 , (COOH),), citric acid (C 8 H 4 , OH, 

 (COOH) 3 ). 



Formate of lime furnishes, according to Hoppe-Seyler, 



