352 



Dr. P. F. Frankland and Mr. J. J. Fox. [June 20, 



in which 



x = percentage of barium formate, 



P — percentage of BaS0 4 actually found, 



B = percentage of BaS0 4 theoretically obtainable from Ba- 



formate, 

 b — ditto from Ba-acetate. 



Thus the calculated composition of 



The total quantity of barium salts of the volatile acids obtained 

 from the fermented liquid thus amounted to 12*1425 grams ; of 

 which probably about 1 gram was barium formate. 



Taking the whole of the barium salts as barium acetate, the quan- 

 tity of volatile acid produced in this fermentation amounted to 

 5' 7141 grams calculated as acetic acid. 



Fixed Acids, Sfc. — The mode of dealing with the residue left after 

 distilling off the volatile acids was somewhat modified in this case. 

 The calcium was precipitated with sodium carbonate and filtered off; 

 after which the filtrate was acidulated with hydrochloric acid, and 

 repeatedly shaken with ether to remove any lactic or succinic acids ; 

 from the residue insoluble in ether, a quantity of mannite amounting 

 to 15" 716 grams was recovered. The ethereal extract was evapo- 

 rated, neutralised with sodium carbonate, again evaporated, and then 

 extracted with strong alcohol (97 per cent.) to dissolve out any 

 sodium lactate, but none was found ; on the other hand, the sodium 

 salt insoluble in alcohol on acidulation and extraction with ether 

 yielded 0*034 gram succinic acid. 



Thus the results obtained in the second fermentation were essen- 

 tially the same as those yielded by the first, with the exception that 

 in addition to ethyl alcohol and acetic acid a small proportion of 

 formic acid was also produced, this is possibly to be accounted for as 

 the result of a secondary action of the ferment on the acetic acid 

 produced in the first instance. This conversion of acetic into formic 

 acid being a process of oxidation, may be dependent upon the accession 

 of air to the liquid at the close of the main fermentation. 



Tn this case the fermenting liquid was allowed to remain in the 

 incubator at 38 — 40° C. for three months, and then at the ordinary 

 temperature of the air for nearly two months more. 



The alcoholic portion was unfortunately lost, but the volatile acids 

 yielded the following barium salts : — 



Fraction III 



Barium acetate. 

 . 0-6281 



Fermentation of Mannite No. 3. 



