326 SUBSTANCES FOUND TO POSSESS 



position of sugar. Sugar therefore forms mannite, 

 lactic acid, and vegetable mucus ; and if, as is often the 

 case when the temperature of the fermenting liquid is 

 kept between 30 and 40, (86 and 104 P.,) no hydro- 

 gen be evolved, this gives rise to non-hydrogenous 

 products, and accounts, according to Schmidt,* for 

 the production of succinic acid, which he found in all 

 liquids fermented in this manner. 



As the opinion that in all the different periods of 

 fermentation the sugar of grape juice undergoes only 

 one transformation, viz. that into alcohol and car- 

 bonic acid, has been found utterly erroneous, we may 

 expect, in future, that the careful analysis of large 

 quantities of wine will discover new varieties of sub- 

 stances in different kinds of wine. 



ODORIFEROUS SUBSTANCES WHICH DEPEND ON THE 

 PLACES WHERE THE GRAPES ARE GROWN. 



Under this head, I understand, besides those sub- 

 stances in wine which determine the nature of the 

 odoriferous ingredients already treated of, more parti- 

 cularly ethereal oils, which exist in abundance in the 

 vegetable kingdom, and appear in all parts of vege- 

 tables, and even in fruits. We perceive in the juice of 

 single grapes, muscadels, for instance, aroma com- 



* Handworterbuch, v. Fogg, Bd. 3, s. 124. 



