334 On the Caltivaiion of the Vine, 



is presented by the expressed juice of grapes which have come 

 to perfect maturity. 



When the must is very aqueous the fermentation is slow 

 and difficult, and the wine arising from it is weak, and very 

 susceptible of decomposition. In this case the antients were 

 accustomed to boil their must : by these means they caused 

 the supernatant water to evaporate, and brought back the 

 liquor to the proper degree of thickness. This process, al- 

 ways advantageous in the northern countries, and in general 

 wherever the season has been rainy, is still practised. Maupin 

 has even contributed to make this method be more adopted, 

 in proving, by numerous experiments, that it may be used 

 with advantage in almost all the wine countries. It however 

 appears to be useless in warm climates ; it is not applicable 

 but in cases when the season having been rainy has not per- 

 mitted the grapes to attain to the proper degree of maturity, 

 or when the vintage has taken place during wet or foggy 

 weather. 



There are some countries where baked piastre is mixed 

 with the grapes to absorb the excess of humidity they may 

 contain. The custom established in other places of drying 

 the grapes before they are fermented is founded on the same 

 principle. All tbese processes tend in an essential manner to 

 remove the humidity with which the grapes may be impreg- 

 nated, and to present a thicker juice to fermentation. 



3d, The juice of ripe grapes contains tartar, which may 

 be shown in it merely by concentrating the liquor, as we have 

 observed: but verjuice furnishes a still greater quantity; and 

 it is generally true that grapes give less tartar the more sugar 

 they contain. 



The marquis de Bouillon extracted from 2J wine pints of 

 must about 10 dwts. of sugar and \\ dwt. of tartar. It ap- 

 pears from the experiments of the same chemist, that tartar 

 as well as sugar concurs to facilitate the formation of alcohol. 

 To obtain three times as much ardent spirit, nothing is ne- 

 cessary but to increase the proportion of the tartar and the 

 sugar. 



The same chemist has also proved that must deprived of 



its 



