THE GBAPE. 19 



able difference. The fruit appears, therefore (and this 

 agrees with Couverchel's experiments upon the ripening 

 of fruits), during the latest period of development, to 

 have an individual life, and to be comparatively inde- 

 pendent of the plant. 



But, if the composition of the soil is of considerable 

 moment to the development of the plant, and conse- 

 quently to the formation of good fruit, the temperature 

 of the region in which the vine grows exercises a no 

 less important influence upon it. 



In districts where the summer is sufficiently long 

 and warm, and the temperature during the whole year 

 never sinks below a certain minimum, the vine pro- 

 duces nothing but ripe and well-flavoured grapes. 

 But when the vine yields exuberantly, the quantity of 

 wine depends entirely upon the temperature. 



Boussingault has given us some valuable information 

 with respect to the quantity of alcohol produced per 

 hectare (two and a half acres) of vineyard, taking into 

 consideration the temperature of the air during the 

 summer and the whole period of culture.* 



The production of alcohol depends necessarily upon 

 two substances, upon the quantity of sugar which 

 is formed per hectare vineyard, and the quantity of 

 albuminous matter afterwards produced, or if we may 

 assume that a sufficiency of albumen is always to be 

 found in grape juice, then ifc depends on the sugar 

 alone. 



* Ann. de Ch. et de Phys. torn. Ixiv. . 176. 



