FERMENTATION. ^243 



1st. When the liquor in the vat is heated by means of the 

 solution of sugar, the temperature is raised to 12° or 14°,* 

 and this causes the fermentation to take place more 

 speedily. 



2d. By covering the vat, the liquor is secured from expe- 

 riencing those variations of atmospheric temperature, which 

 may either hasten, retard, or suspend fermentation. 



3d. The heat developed in a close vat is more intense than 

 that in an open one, and the decomposition of the must is 

 consequently more perfect. 



4th. The addition of sugar gives rise to an additional 

 quantity of alcohol. 



5th. The head of the liquor is much less apt to become 

 sour. 



6th. The wine is more equal and less susceptible of 

 change. 



7th. The loss of alcohol by evaporation is less than in un- 

 tsovered vats. 



As next to that of corn the harvest of wine is the most 

 important one, inasmuch as it forms our principal article of 

 commerce with foreign countries, too much care cannot be 

 taken in the manufacture of it.t 



It is customary with most of our proprietors of vine- 

 yards to plant upon the same soil vines of diflerent kinds 

 of grapes, the fruits of which do not arrive at maturity at 

 the same time. This custom is particularly practised in 

 those vineyards which produce wines of middling quality ; 

 and it has been introduced and continued in them, because 

 the different kinds of vines do not flower at the same time, 

 but are some of them earlier than others, and some of them 

 more sensible to the influence of the changes of the at- 



[* If the centigrade thermometer, the correspondingr deirrees of Fah- 

 renheit's are 53.6° and 57.2° ; if Reaumur's 59° and^GSi^. — Tr.] 



t The mean value of the products of the vineyards of France from 

 1805 to 1809, was about 36,000,000 hectolitres of wine, (~ 7,548,235 

 pipes, 1 hhd. 27 gals.) According to an examination afterwards made 

 b^ the board for the levying of indirect duties, which claimed some 

 right over this liquor, the valuation here mentioned is believed to be 

 far short of the truth. 



Vineyards which had then been recently planted, and consequently 

 produced but little wine, now afford abundant crops; and as new 

 ones are constantly planted, I am convinced that the product of the 

 vintage is very considerably augmented. It is I think probable, that 

 the harvest of wine equals at this time nearly 50,000,000 hectolitre*, 

 <= 10,483737 pipes, 1 lihd. 5 gals.) 



