l6 On the Cultivation of the Vine, 



which take place in the operation can be referred only to the 

 departure of thofe fubftances which are volatilifed or precipi- 

 tated. 



Thus, by (ludying the nature of thefc fubftances, and af- 

 certaining their conltitucnt principles, it will be eafy for us 

 to judge of the changes which rriufft have been produced in 

 the nature of the frrit materials of fermentation. 



The materials of fermentation are the fweet and faccharine 

 principle diluted in water. This principle is formed of fugar 

 and extractive matter. 



The fubftanec volatilifed is the carbonic acid gas, and that 

 precipitated is a matter analogous to the ligneous fibre mixed 

 with potam. 



The principal product, of fermentation is alcohol. 



It is evident that the tranfition of the faccharine principle 

 to alcohol cannot be conceived but by calculating the differ- 

 ence which mn(l be produced in the faccharine principle by 

 the departure of the principles that form carbonic acid gas 

 which is volatilifed, and the depofit which is precipitated. 



Thefe principles are, in particular, the carbon and the 

 oxygen : here, then, we find carbon and oxygen taken from 

 the faccharine principle by the progrefs of fermentation ; 

 but in proportion as the faccharine principle lofes its oxygen 

 and its carbon, the hydrogen, which forms the third con- 

 ltituent principle, remaining the fame, the characlers of the 

 latter element mutt predominate, and the fermenting mafs 

 mud attain to that point at which it will only preterit aft 

 inflammable fluid. 



In proportion as the alcohol is developed, the liquid changes 

 its nature ; it no longer has the fame affinities, nor, conte- 

 quently, the fame dfilblving power. The fmall quantity of 

 extractive principle which remains after having efcaped de- 

 compofition is precipitated with the carbonat of potafh ; the 

 liquor becomes clear, and the wine is made. 



Vinous fermentation, then, is nothing, but the continued 

 departure of carbon and oxygen, which produces on one 

 hand the carbonic acid 3 and on the other alcohol. The ce- 

 lebrated Lavoifier fu ejected to calculation all the phaenomena 

 and refults of vinous fermentation, comparing the products 

 of the decompofition with its elements. He aflumed as the 

 hatis of his calculations the data furnifhed to him by analyfis 

 both in regard to the nature and the proportions of the con- 

 ftitucnt principles before and after the operation. We mall 

 here tranferibe the refults obtained by this great man. 



$lflteriak 



