VINEGAR FERMENT AND ITS CONDITIONS OF LIFE. 35 



acidification when brought into a fluid suitable for the formation 

 of acetic acid. 



The mother of vinegar occurs generally only in fluids which, 

 besides alcohol, contain large quantities of extractive substances, 

 for instance, wine or beer. After the ordinary vinegar ferment 

 has for some time grown upon the surface of these fluids a coat- 

 ing is formed which acquires a thickness of up to j- inch, and 

 such consistency, that with some care, it can be lifted as a cohe- 

 rent mass from the fluid. The mother of vinegar then represents 

 a very elastic transparent mass of a yellowish-white color and 

 closely resembles an animal hide swelled to a high degree by treat- 

 ment with water. 



Upon the side of the skin exposed to the air numerous molds 

 frequently settle and form complete sods of the well-known gray 

 green or yellow color. This is, however, only a secondary phe- 

 nomenon, the mother of vinegar being especially adapted as a 

 basis for the development of molds. By exposure to the air, best 

 upon a porous support (a plate of brick or gypsum), the mother 

 of vinegar quickly decreases in bulk and finally dries to a very 

 thin layer resembling paper. Viewed under the microscope the 

 mother of vinegar appears as a mass entirely devoid of structure 

 in which numerous individuals of the vinegar ferment are 

 imbedded. 



Several opinions have been expressed as to the nature of the 

 mother of vinegar, and among others that it is a special variety 

 of vinegar ferment, w r hich, however, cannot be accepted as correct, 

 it being far more probable that its formation depends on the 

 nature of the fluid upon which ordinary vinegar ferment grows. 

 As previously mentioned, the mother of vinegar reaches develop- 

 ment upon young wine and beer, and these fluids always contain 

 certain quantities of albuminous substances in solution. Now it 

 is very probable that the mother of vinegar consists of pecu- 

 liarly changed albuminous substances eventually also of carbo- 

 hydrates and that innumerable organisms of the vinegar ferment 

 are distributed throughout the mass which cause the acidification 

 of fluids to which it is transferred. This view is supported by 

 its composition, with regard to its organic substance, as deter- 

 mined by Mulder. 



