On the AimJyfis of JVine. 375 



3d, Tartar. Tartar exifts in verjuice: it is found alfo in 

 nmtl : it concurs to facilitate the formation of alcohol, as we 

 have already obfervcd from the experiments of Bullion. It 

 depofils itfelf on the fides of the calks in coufcquence of reft, 

 and forms there a cruft of greater or lefs thicknefs, rough, 

 with cryftals very badly determined. Some time before the 

 vintage, when the vcfl'cls are getting ready for receiving it, 

 the calks are opened, and the tartar is taken out, to be em- 

 ployed in commerce and for various other purpofes. 



Tartar is not furniflicd by all wines in the fame propor- 

 tion. Red wines cive more than the white. The hijrheft 

 coloured and thickell generally give the moll. 



The colour of the tartar alio varies very much, and it is 

 called red or zohite, according as it is produced from either 

 of thefe wines. 



This fait is very little folnble in cold water: it is much 

 more fo in boiling'water. It fcarcely diO'olves in the mouth, 

 and refills the prelTure of the teeth. 



It is freed from its colouring principle by a fimple procefs, 

 •and is then known under the name of cream of tartar. For 

 this purpofe it is dilVolved in boiling water, and, when the 

 water is faturated, the folution is put into earthen velfcts to 

 cool : as it cools, it precipitates a llratuni of cryllals which 

 are already alniolt free from colour. Thefe cryftals are again 

 diflblvcd in boiling water: four or five per cent, of an argil- 

 laceous and fandy kind of earth, found at Murviel, near 

 Montpellier, is diifufed through the folution, and it is then 

 evaporated to a pellicle. On cooling, it precipitates white 

 cryllals, which being expofed in the open air on cloths for 

 lome days, acquire that whitenci's which belongs to cream of 

 tartar. The mother-waters are referved for being employed 

 in new folutions. Such is the method praftii'cd at Mont- 

 pellier and in its environs, where the principal part ot the 

 manufaftoricB of cream of tartar are ellablillicd. 



The tartar is employed alfo as a flux : it is attended with 

 the double advantage of furnilliing the carbon neceflary for 

 the deoxygenation oT the n)etals, and alfo alkali, which is one 

 of the belt fluxes known. 



Tartar is purified alfo by calcination. Its acid is decom- 

 pofed and deftroved by this procefs, and there remains then 

 nothing but the alkali and the charcoal : the alkali is diflolved 

 in watf^r, the licpior is filtered, and, being then concentrated, 

 that (alt known in the fhops under the name oi fait of tartar ^ 

 or carhuiatf of pola/h, is obtained. 



The alkali furnilhcd by tartar amounts only to one-fourth 

 of its weight. 



A a 3 4th, £,v- 



