(ENA^THIN GUM. 271 



which resolution is speedily effected, when the wine 

 becomes ropy (p. 127) ; or of the transformation of 

 tartaric acid into gum, or vegetable mucus (p. 114). 



It cannot be denied that some cellared wines increase 

 in consistency and sweetness till they resemble syrup. 

 This change may be effected by a large amount of 

 gum or vegetable mucus, and if these substances are 

 really formed from tartaric acid, we have discovered 

 how it is that wine becomes sweeter and more con- 

 sistent. 



The subject is sufficiently important to deserve ex- 

 amination, although we can hardly expect that an 

 analysis of wine will make us accurately acquainted 

 with it ; for supposing a larger quantity of gum to be 

 found in old than in young wines, which considering 

 their greater consistence is not improbable, who can 

 assure us that the old wines did not originally con- 

 tain a larger proportion of gum ? 



That vegetable mucus is produced from sugar, and 

 cellulose from tartaric acid, is well known, and the 

 approximation in kind, and identity in combination of 

 cellulose, and vegetable mucus or gum, and the de- 

 crease in acidity of old wines is equally acknowledged. 

 I alluded to the diminution of acids in wine (p. 113) ; 

 as regards the chemical composition of these sub- 

 stances, it would make no difference whether sugar 

 or gum were formed. 



