340 On the Cultivation of the Vine, 



This danger may be prevented by saturating the gas in 

 proportion as it is precipitated on the floor, by scattering in 

 several places milk of lime, or quicklime. A place rendered 

 noxious by this pernicious gas may be purified by throwing 

 upon the floor and against the walls quicklime diluted in 

 water : a caustic alkaline ley, such as soapmakers' ley or am- 

 monia, will produce a similar effect. In all cases the gaseous 

 acid instantly combines with these matters, and the external 

 air descends to occupy its place. 



3d, Formation of Alcohol. — The saccharine principle exists 

 in must, and makes one of its principal characters : it dis- 

 appears by fermentation, and is replaced by alcohol 3 which 

 essentially characterizes wine. 



We shall mention hereafter in what manner this phaeno- 

 menon, or this interesting series of decompositions and pro- 

 ductions, may be conceived. Our business at present is to 

 indicate the principal facts which accompany the formation 

 of alcohol. 



As the object and effect of spiritous fermentation are 

 merely the production of alcohol by decomposing the sac- 

 charine principle, it thence follows that the formation of the 

 one is always in proportion to the destruction of the other, 

 and that the alcohol will be more abundant as the saccharine 

 principle is greater : for this reason, the quantity of alcoJiol 

 may be augmented at pleasure by adding to the must the 

 sugar which seems to be wanting. 



It invariably follows from these principles, that the nature 

 of the vintage in fermentation is every moment modified and 

 changed : its smell, taste, and other characters, are continu- 

 ally varying. But as there is a very constant progress in the 

 process of fermentation, it may be followed in all its changes, 

 which may be considered as invariable signs of the different 

 states through which the vintage passes. 



1st, Must has a sweetish odour, which is peculiar to it. 

 2d, Its savour is more or less saccharine. 3d, It is thick, 

 and its consistence varies according as the grapes are more 

 or less ripe, more or less saccharine. I have found by ex- 

 perience that some marked 75 degrees of the areometer, and 

 others only from 40 to 42. It is exceedingly soluble in water. 



Scarcely 



