ADULTERATION OE WINE. 361 



The same may be said of clay or sand when used 

 for clarifying. 



Chalk or marble added to young wine for the purpose 

 of withdrawing excess of tartaric acid cannot after- 

 wards be detected ; the superfluous tartaric acid com- 

 bines with a portion of lime added to it, and is preci- 

 pitated, whilst any excess of chalk remains undissolved. 

 The case is different when wines that have become acid 

 have their free acids removed by means of chalk, potash, 

 or soda. The alkali thus used remains in the wine, 

 and if a mixture is to be called adulteration it is one. 



If potash or soda is used to saturate the acetic 

 acid in wines which have become acid, a small excess 

 of alkali will first alter the colour, and the flavour will 

 never be as good as before. The wine becomes sharp 

 and salt. The acetic acid has been produced from the 

 alcohol of the wine, and in order to make the wine 

 sufficiently strong, alcohol must be added at the same 

 time as the carbonate of potash. This adulteration is 

 proved to have taken place, if w r hen the wine has been 

 evaporated, and the residue distilled with sulphuric 

 acid, a great deal of acetic acid is obtained. (In pure 

 wine the acetic acid is free.) Or the wine is evaporated 

 to dryness and treated with alcohol. Alcohol of 53 

 per cent, dissolves acetate of soda ; of 95 per cent., ace- 

 tate of potash. If chalk has been employed to combine 

 with the acetic acid, the wine gives a copious pre- 

 cipitate with oxalate of ammonia, whilst genuine 

 wine yields very little precipitate. 



