FERMENTATION. 75 



with the torn walls of the pulp. Sugar, gum, and vege- 

 table mucus, are found in the juice, albumen in the torn 

 walls. These four together are the material out of 

 which ferment cells are constructed, a portion of one 

 of the last two serving to engender fermentation, 

 whilst the ferment is in process of formation. 



If we call to mind the very considerable quantity 

 of albumen found in a solid state in the walls of those 

 cells in which the juice is enclosed (p. 35), and that 

 free tartaric acid is capable of dissolving solid albu- 

 minous bodies (p. 36) ; and remember, further, that 

 free tartaric acid exists in every kind of grape juice 

 (the re-action of which is therefore always acid, even 

 though the excess of sugar gives it a sweet taste), we 

 shall be able to form an idea of the advantage derived 

 from mixing a liquid containing acid with the torn 

 walls of the cells of the grape pulp, rich as they are in 

 albuminous matter. Dopping and Struve thought they 

 saw ferment originate in carbonic acid or hydrogen 

 gas, if we only so far throw doubt on the results 

 obtained by them, as to think they did not, perhaps, 

 completely exclude the air, and, according to G-ay- 

 Lussac, very little air is necessary to cause fermenta- 

 tion, then we willingly accept these statements by 

 which they assert that no good formation of ferment 

 takes place without larger admission of air. A little 

 air may occasion fermentation, but to the formation of 

 good ferment a well-regulated admission of air is neces- 

 sary. In the same way, though but little oxygen is 



