THE GRAPE. 39 



as much. We will not, however, dispute about the 

 formula, but only intimate that more oxygen exists in 

 it than in sugar, cellulose or gum, or than is neces- 

 sary to form water. Pectin is not necessary for fer- 

 mentation, for yeast, which contains none, is sufficient 

 to ensure good fermentation in sugar and water. As, 

 however, pectin is found in all sweet fruit juices, and all 

 these, except when prevented by particular circum- 

 stances, ferment easily and strongly, and as nothing 

 has been ascertained with respect to the disappear- 

 ance of pectin during fermentation ; therefore atten- 

 tion must be directed to this point before studying 

 fermentation, and the question must be asked, Does 

 pectin assist in the formation of wine or not ? and, if 

 so, how ? 



"We must leave those to answer this query who are 

 able to watch the traces of alteration in pectin on the 

 spot where wine is made. 



GUM, OB, VEGETABLE MTJCTJS. 



Among the substances found in grape juice, and 

 particularly deserving of notice in connexion with the 

 formation of ferment, is gum or vegetable mucus, it 

 being unnecessary at present to make a distinction 

 between them. Gum is C 12 H 10 O 10 ; vegetable 

 mucus, C 14 H 19 O 19 . The mode of preparation of 

 pectin which is given by Fremy, assumes that gum 

 or vegetable mucus, being insoluble in alcohol, will be 



