.328 Oil the Cultivation of the Pine, 



proportioned to the temperature of the atmosphere *. Bacon 

 recommends the immersion of vessels containing wine, in the 

 eea, to prevent its decomposition. Boyle relates, in his Treatise 

 on Cold, that a Frenchman, to keep his wine in the state of 

 must, and preserve to it that svveetness of which some persons 

 are fond, closed the cask hermetically and immersed it in a 

 well or a river. In all these cases the liquor was not only 

 l:ept in a temperature very unfavourable to fermentation, but 

 it was secured from the contact of the air, which checks, 

 or at least moderates, fermentation. 



An extraordinary phaenomenon, but which seems con- 

 firmed by a sufficient number of observations to merit full 

 belief, is, that fermentation is slower as the temperature has 

 Veen colder at the time of collecting the grapes. Rozier found 

 in 1769 that grapes (•ollectcd on the 7th, 8th, and 9th of 

 October remained in the vat till the 19th without showing 

 the least sign of fermentation : the thermometer in the morn- 

 ing had been at 3| degrees below freezing, and maintained 

 itself at + 4. The fermentation was not completed till the 

 25th; while similar grapes collected on the 16th, at a tem- 

 perature much less cold, terminated their fermentation on the 

 21st or 22d. The same thing was observed in 1740. 



In consequence of these principles, it has been recom- 

 mended to place the vats in covered places ; to remove them 

 from damp and cold places; to cover them, in order to mo- 

 derate the cold of the atmosphere ; to heat again the mass by 

 introducing boiling must ; and to make choice of a warm day 

 for collecting the grapes, or to expose them to the sun, &c. 



2. Influence of the Jir on Fermentation, 

 We have seen in the preceding article that fermentation 

 may be moderated and retarded by withdrawing the must 

 from the direct action of the air, and keeping it exposed to a 

 cool temperature. Some chemists, in consequence of these 

 facts, are of opinion that fermentation can take place only 

 bv the action of the atmospheric air ; but a more attentive 

 ob.^ervation of all the phenomena it presents in its different 

 states will enable us to set a just value on all the opinions 

 which have been entertained on that subject. 



• Quaiat. Nat. 27. The 



