0« the TaHaream Salts'. vit 



Having formed by theCe fimple methods the proportions of water and tartareous acid, 

 and of oxide of antimony in emetic tartar, there remained nothing more for Citizen 

 Thenard to determine than the proportion of pdt-a(h, which would have been cafy for him 

 to have come at by fabtrafting the quantities already known from the fum total employed ; 

 but lie chofe rather to have recourfe to experiment, and by that means to verify his former 

 operations. He therefore took lOO new parts of emetic, calcined them in a crucibje till 

 the fartareous acid muft have been decompofed, and afterwards treated the refidue with 

 weak nitric acid. He preferred this acid to all the others, becaufe it does not diflblve the 

 oxide of antimony, and the ley afforded him by evaporation, 30 parts of nitrate of pot- 

 afh. He might have deduced the quantity of pot-afli contained in thefe 30 parts of nitre 

 fronm the analyfis given by many chemifts, but the refults of their analyGs being very Jif- 

 ferentv he could not know which to depend on. He therefore choiJe to refume this ope- 

 ration himfelf, and he found that this fait is formed of 53 parts of pot-afh, and 47 of nitric 

 acid,, and accordingly that 30 parts of nitre contained 16 parts of pot-afli. Whence we 

 may eftabliili the following proportions for lOp patts of emetic; namely, antimony 38, 

 tartareous acid 34, pot-afli 16, water 8, and lofs 4. 



The aqiduilous tartrite of pot-afh being formed according to the analyfis made by Citizea 

 Tl?eji;^r4 of J 7 parts of tartareous acid, 33 of pot-afl>, and 7 of water, atwi the tartareous 

 acid dividing itfelf in the fabrication of tartar emetic, between the pot-afli and the oxide 

 of antimony, we may conclude, that 100 parts of tartar emetic contained 34 parts of tartrite 

 of pot-a(h, 54 of tartrite of antitnony, and 8 of water, becaufe loo parts of neutral tartrite 

 of pot-afli- contained 48 parts of acid, 43 of pot-afli, arid 7 of water. 



Citizen Thenard having obtained by analyfis 57 parts of tartareous acid, 33 of pot-afhjf, 

 and 7 of water from the acidulous tartrite of pot-afh ; and having compared the propotv; 

 tapns of the tartrite oj pot-afli and antimony which conflilute emetic tartar, he found that 

 there is in cream of tartar more tartrite of pot-afh than is neceflary to faturate the tartrite 

 Qf antimony ; that this excefs of fait remains in the mother water of emetic tajrtar, and 

 that in order to obtain this laft falt_ia agitate of purity, the cryftals obtainedjlrpm. the firfl:- 

 evaporation only mufl: be collefte4..,i ■ ' 



"I 



CONCLUSION. 



The experiments contained in the memoir, of which the Commiflaries have given this 

 account are numerous, interefting, and made as to them appears, with ail the accuracy 

 which chemical methods are fufceptible of. They prove that moft of the tartrites cart 

 combine with each other, and form triple falts which have particular properties. ThcrB 

 are fome in faft which have for their bafis two alkalies, others an alkali and an earth, 

 others an alkali and a metal, and others an earth and a metal. What is remarkable'js, 

 that moft of thefe bafes which are feparated by the alkalis from their fimple combinations 

 with the tartareous acid> are notfepatated w,h£3;ia.the ftatB.oX triply, fait. 



