£xamiitation of the Purily of Medicines, iife, -J<tt 



The bed diftilled vinegar has a pleafant tafte and fragrant fmell, is perfeftly colourlefs, 

 and twelve parts of it require one of dry vegetable alkali to neutralife it. 



Boracic Acid. 



ON account of the hlgli price which this acid bears, we often meet with it intcntiohaHy 

 adulterated with Venetian talc, afbeft, &c. 



Genuine boracic acid is foluble in five times its quantity of boiling ardent fpirit, and 

 the folution when fet on fire burns with a green flame. In water it diflblves tardily j 

 when fubmitted to the blow-pipe it fluxes to a perfefl tranfparent glafs if genuine ; it vi- 

 trifies earth and ftones. If it be added in fmall quantities to tartarite of potafli, it tranf- 

 forms it into a very foluble fait. The bed boracic acid is exhibited in fmall hexangular 

 fcaly cryftals, of a (hining filvery white colour. It difcovers only a flight acid tafte, and 

 does not deliquefce in the air. 



Its fpecific gravity is 1,480. 



Tartareous Acid. 



TARTAREOUS acid may very eafily be contaminated with fulphuric acid, either frau- 

 dulently or in confequence of a faulty preparation. 



The admixture of fulphuric acid is foon difcovered, if a fmajl quantity of the tartareous 

 acid be diflblved in diftilled water, and a few drops of a folution of acetite of lead arc 

 added to it : by this means a white precipitate is afforded, which, by the addition of a few 

 drops of pure nitric acid, will be entirely rediflblved if no fulphuric acid is prefenfc. The 

 prefence of tliis acid is ftill more readily manlfefted by adding to the tartareous acid dif- 

 folved in diftilled water a few drops of a folution of nitrate of barytes, in confequence of 

 which fulphate of barytes will immediately be generated. 



Pure cryftallized tartareous acid does not change by expofure.to air; It is very foluble 

 in water, and poflefles a grateful acid tafte. 



Acid of Anther. 



WE find this acid wonderfully adulterated fometimes with fulphuric acid and all its 

 combinations, fometimes with tartareous acid, and now and then with muriate of am- 

 moniac. 



The fulphuric acid is difcovered by means of nitrate of barytes, or acetite of lead. 



The tartareous acid is difcovered by means of vegetable alkah j for, if this acid be pre- 

 fent, a quantity of tartarite of potafli will be fprmed. 



Muriate of ammoniac is difcovered with refpe6l to one of its component parts (the mu- 

 riatic acid), by the folution of nitrate of filver; and with refpeft to the other (the am- 

 moniac) by adding to the aqueous folution of this fait a little vegetable alkali, and, after 

 heating the mixture, holding over it a ftopper moiftened with acetoijis acid> white fumes 

 will be formed, which indicate that ammoniac is prefent. ,., ^ : 



Pure acid of amber is a cryftalline white fait, of an acid tafte, foluble in twenty-four 

 times its weight of cold water, but in eight when boiling hot, and is volatilized on an ig- 

 nited iron, leaving neither allies nor any other refidue behind. 



Vol. II.— June 1798. R Acid 



