52 



depends on the presence of a sufficient quantity of the 

 matter necessary to fermentation, and these are gene- 

 rally present, at least up to a certain point. Besides 

 this, it is of consequence that the sour grape juice 

 should not contain too much tartaric acid, for this is 

 not entirely removed by the sugar, though rendered 

 for the most part ineffective as far as taste is con- 

 cerned. 



In this case another remedy is employed, and we 

 are obliged to call both this and the addition of sugar 

 (with whatever intention it may be made) adultera- 

 tion; for wine, in the sense in which alone wo are now 

 considering it, professes to be grape juice c'^niged bv 

 fermentation, and nothing more ncr less. The means 

 used are these : chalk is added to a portion of freshly 

 expressed juice (must), and its free acids are -thus 

 withdrawn ; for example, the free tartaric acid existing 

 in the juice, and half the cream of tartar. The por- 

 tion of juice mixed with chalk is exposed to partial 

 evaporation, allowed to cool, and the precipitate de- 

 posited. In this manner a juice is obtained which 

 has been deprived by lime of all its free acids, has 

 gained relatively by evaporation in sugar, and contains 

 the so-called neutral tartrate of potass. Now if to 

 this another portion of the original must be added, 

 the free tartaric acid of the latter combines with the 

 neutral tartrate of potass of the former, and forms a 

 fresh cream of tartar. The whole thus becomes less 

 acid, and its saccharine contents are increased by the 



