142 AMOUNT OF ALCOHOL IX WINE. 



quantity of the substance of which the walls of the 

 ferment cells are composed, and it is decidedly influ- 

 enced by the quantity of gum existing in the grape 

 juice. If during the development of the grapes but a 

 small portion of gum has been formed in them, fer- 

 mentation will certainly ensue, since albuminous mat- 

 ter is of itself sufficient to cause fermentation, with- 

 out being converted into ferment, as is the case with 

 fibrin, gelatine, &c. ; but the fermentation will differ 

 essentially from that in which ferment cells are 

 normally engendered in sufficient quantities ; for which 

 purpose it is not necessary that any portion of sugar 

 should be expended. (P. 64.) 



That the formation of ferment is affected by the 

 weather in a different manner from its decomposition 

 is known, but who can explain the difference ? "We 

 are acquainted with the varieties occasioned by an 

 unequal admission of air. (Pp. 55 to 60.) 



I have only been able to take a superficial view 

 of the many circumstances which affect the produc- 

 tion of a larger or smaller quantity of alcohol, and 

 which must be considered if any one wishes to form a 

 general idea of the causes upon which the variations 

 in the amount of alcohol in different wines depend. 



As yet only a few of these circumstances can be 

 fully explained ; with respect to many others we 

 know that they exist without being able to account 

 for them, and we are quite in the dark as to many of 

 those properties of wine which, though intimately 



