36 VINEGAR, CIDER, AND FRUIT-WINES. 



Composition of the mother of vinegar, according to Mulder : 



Carbon 46 - 8 



Hydrogen ....-' 6 - 4 



Nitrogen 3 - 9 



Oxygen 42< ^ 



According to R. D. Thomson, who also examined the mother 

 of vinegar, its composition is : 



Organic substance .{ C ^ lul Se } about 5 per cent. 



I al lin-ini nrtim snhstaiioe t 



'I albuminous substance 

 J potash, lime 

 I phosphoric acid 

 Water ..... more than 94 



salts . . . i*: ;' - ., " 



These analyses justify the opinion that albuminous substances 

 as well as carbohydrates participate in the formation of the mother 

 of vinegar. (In beer carbohydrates are always present, while in 

 wine extractive substances occur which, at least, are closely allied 

 to the carbohydrates.) An experiment especially made for the 

 purpose conclusively proves that the formation of the mother of 

 vinegar depends on the presence of the above-mentioned sub- 

 stances in the fluid upon which it grows. 



A thick cover of mother of vinegar had formed upon young 

 wine ; this being removed it was in a few days replaced by a new 

 growth, which, however, was not quite so thick. This cover 

 being also removed a third but very slight one was formed until 

 finally a cover of mother of vinegar was no longer developed 

 upon the fluid, but only normal vinegar ferment. The explana- 

 tion of this phenomenon is that with the decrease of nitrogenous 

 substances in the wine, the conditions for the development of 

 mother of vinegar became constantly more unfavorable until 

 finally nothing but vinegar ferment could form. By transferring 

 a piece of mother of vinegar to a fluid composed of alcohol, water, 

 and some old wine (hence such as contained only very small quan- 

 tities of nitrogenous substances) the slimy mass remained floating 

 in the fluid without increasing or undergoing alteration, while the 

 surface became covered with ordinary vinegar ferment and acidi- 

 fication proceeded in a normal manner. 



The formation of mother of vinegar can always be successfully 

 attained by exposing young wine to the air until the commence- 



