On the Analyjis ofll^me. 1 29 



tafte, an odour flighlly cmpyreumatic, leaves a fenfation of 

 harfhnefs on the tongue, &;c. When well filtered and left 

 in a jar, it fuffers to be precipitated a confiderable quantity 

 of extraftive matter. It then becomes covered vi'ith mouldi- 

 nefs, and in that ftate feems to approach the acetous acid. 

 It may be purified by diflillation, which feparates from it 

 a large quantity of extractive matter; and it is then Icfs 

 liable to be decompofed by putrefaftion. 



This acid precipitates the carbonic acid from its combina- 

 tions : it diflblves with facility the greater part of the me- 

 tallic oxides : it forms infoluble falts with lead, filver, and 

 mercury ; and feparates the metals from all their folutions in 

 acids. 



This acid forms alfo an infoluble fait with lime. If abun- 

 dance of lime water be mixed with wine, it precipitates the 

 acid, which carries with it all the colouring matter. This 

 acid, then, is of the nature of the malic acid. It is always 

 mixed with a little of the citric acid ; for, when digefted ou 

 oxide of lead, befidesthe infoluble precipitate which is formed, 

 there is produced a citrate, w hich mav be (liown in it by the 

 common means. 



This malic acid difappcars bv the acetification of the wine •. 

 in well made vinegar, nothing exirts but acetous acid. This 

 transformation of the malic acid into acetous acid naturally 

 explains why wine which has only begun to turn four can- 

 not be employed in manufae^^uring acetite of lead : in this 

 cafe there is formed an infoluble precipitate, with the pro- 

 duftion of which I was greatly embarralled till I learned 

 the reafon (jf it. For a long time, C. Berard, my aflbciale 

 in my manufactory of chemical productions, added nitric 

 acid to four wine to give it the property of forming a foluble 

 fait with lead. I was then of opinion that the acid of wine 

 was by thcfe means oxygenated, while the effeCl really pro- 

 duced was to haden the decompofition and converlion of the 

 malic acid into vinegar. 



The exiftence of the malic acid in wine in different propor- 

 tions, ferves to throw fome light on a phaenomenon of the 

 higheft importance in regard to the diftillation of wines, and 

 the nature of the fpirit produced from them. Every body 

 knows, not only that all wines do not give the fame quantity 

 of fpirit, but that the fpirits produced from them are far from 

 being of the fame quality. No one is ignorant that beer, 

 cyder, perry, and fermented farinaceous fubllances, give little 

 fpirit, and always of a bad quality. Careful and repeated 

 diftillation may, indeed, correct thefe faults in a certain de- 

 gree, but never dcllroy them completely. Thefe conftant 



Vol.. XI. I relulls, 



