I 163 ] 



XXiy. On the different Qualities of Wines, and the Me- 

 thods of preserving and ameliorating them. By M. Du- 



PORTAL, M.D. *. 



XN niv preceding Dissertation f on Fermentation, I took 

 particular care to dtscnbe that ppecies of it which tLiriiishes, 

 as its product, an intoxicating liquor, and is especially em- 

 ployed in procuring this liquor from the grape. This con- 

 stitutes ivine, so aorecable a beverage to mankind in ge- 

 neral, and in which the constituent princip es are the most 

 intimately combined. \n all times, therefore, this useful 

 and plcas.ng liquor has occupied the attention as well of 

 the chemists as of the makers of wijie. Among the for- 

 mer, M, Chaptal appears to me to have thrown the most 

 light upon the sui)ject of wine. Whoever attentively reads 

 what this learned chemist has written upon the causeij 

 which influence the quality of wine, the means made use 

 of ID preserve and ameliorate it, the vessels proper to keep 

 it in, and upon the changes and degeneration of which it 

 is susceptible, cannot fail of assenting to the theory, bv 

 which he accounts lor a multitude ot facts and numerous 

 circumstances which have hitherto been considered inex- 

 plicable. A detail of all he has written upon this subject, 

 although in itself very important, is adapted rather to a 

 treatise of agriculture than for a chemical journal ; I shall 

 therefore confine myself to those parts of his writings which 

 relate directly to the general chemical llieory of the prepa- 

 ration of wine. 



J. Of the Causes which injivence the Quality of Wines. 



The vine at the present dav grows almost every where, 

 but particularly between the 35th and 52d degrees of lati- 

 tude. The wine furnished bv it, is hot however the same 

 in all countries. This liquor, in general, is onlv good in 

 countries between the 40tb and 50th degrees. Considera- 

 ble ditTerence also exists within these latitudes, whence are 

 produced au infinite variety of wines, which cannot be 

 conlounded with each other, notwithstanding the chemical 

 composition of all of them is pretty nearly the same. 



Among the causes which have an influence upon the 

 quality of wines, M. Chaptal enumerates : 



1. The different spi-cies of the ( ultivated vines. 



2. The variety of eliiuates where they grow. 



• /InnalfS lie Clitmie, IRI I. 



■t ice Phil, M.ig, vol. xxxviii. pages C'21 aud I'.'o. 



L 3 * 3. The 



