VINEGAR FERMENT AND ITS CONDITIONS OF LIFE. 27 



therefore, be said that the entire art of the manufacture of vinegar 

 consists in an accurate knowledge of the conditions of life of the 

 vinegar bacteria and in the induction of these conditions of life. 

 As long as the latter are maintained, the process of the formation 

 of vinegar will go on without disturbance and the origination of 

 new generations of vinegar ferment be connected with the con- 

 version of certain quantities of alcohol into vinegar. 



CHAPTER III. 



THE VINEGAR FERMENT AND ITS CONDITIONS OF LIFE. 



A. The Vinegar Ferm,ent. 



XOTHING is as yet known about the origin of the vinegar 

 bacteria, but experiments have shown these organisms to be every- 

 where distributed throughout the air and to multiply at an enor- 

 mous rate when fluids of a composition suitable for their nour- 

 ishment are presented to them. A fluid especially adapted for 

 this purpose is, for instance, thoroughly fermented, ripe wine, its 

 exposure in a flat vessel and at the ordinary temperature of a 

 room being sufficient to induce the augmentation of the vinegar 

 bacteria reaching it from the air. 



This experiment is, however, only a certain success when exe- 

 cuted with ripe wine, by which is meant wine which shows but 

 little turbidity when strongly shaken in contact with air and 

 exposed in a half-filled bottle to the air. Young wine contains a 

 large quantity of albuminous substances in solution, and is espe- 

 cially adapted for the nourishment of an organism (saccharomyces 

 mesembryanthemum) belonging to the saccharomycetes. It develops 

 upon the surface of such wine as a thick white skin w r hich later 

 on becomes wrinkled and prevents the growth of the vinegar 

 ferment. A fluid well adapted for the nourishment of the vine- 

 gar ferment, and which may be used as a substitute for wine for 

 its cultivation, is obtained by adding 5 to 6 per cent, of alcohol 

 and about J per cent, of malt extract to water. 



