524 RIPENING FRUIT REQUIRES WARM NIGHTS. 



that, where a burning sun has been shining for three 

 months, and the ground is excessively heated, there must of 

 necessity be a very high teinperature at night. In fact, in 

 Persia, which is nearly the climate of Candahar, the midnight 

 temperature of August has been known to be as high as 108°; 

 and it is certain that in all such countries the difference 

 between the temperature of the day and night, at the hot season of 

 the year, when Grapes ripen, is inconsiderable. We may, there- 

 fore assume that a night temperature of from 70° to 80° ought 

 to be secured when Grapes are ripeniag. 



At that period of their existence much atmospheric moisture 

 is unnecessary, or rather injurious to Grapes, for it will inevi- 

 tably cause the Vine to break into a multitude of little 

 branches to the impoverishment of the fruit. In the Vine 

 countries the air is parching ; Mr. Atkinson's paper curled up 

 in Candahar, while he was writing on it ; and the Vine wiU bear 

 such a climate well, if it is gradually inured to it, provided the 

 roots are in a moist soil, and there is a free circulation of 

 air. It is to be recollected that when a tree is ripening its 

 fruit, it is in quite a different condition from what occurs when it 

 is flowering. At the latter period its energies are all directed 

 to organizing itself, and consolidating the parts that may have 

 been formed ; it is growing, and hardening its growth. But at 

 a later period organization and consolidation are accom- 

 plished, and it is the elaboration of the fluids, stored up within 

 the plant, that has to be provided for. The fruit of such a 

 plant as the Vine is incessantly sucking fluids out of the 

 branches ; but that fluid is little more than water and mucilage. 

 It is after reaching the fruit that it thickens by evaporation, 

 and changes owing to chemical combinations brought about by a 

 variety of phenomena ; the result of which is the conversion of 

 acid into sugar, and the creation of the delicate flavours which 

 give the Grape its value as a fruit. 



