276 ESSAY XXV. 



highly interesting event. I think I can show that they may 

 all be converted into one ; and that this primitive acid is 

 contained in the purest spirit of wine. The following are 

 my proofs : 



(1) If the residuum of dulcified spirit of nitre be boiled 

 with a large quantity of nitrous acid, care being at the same 

 time taken to condense the vapours by a proper apparatus ; 

 and if the liquid which has passed over be saturated with 

 vegetable alkali, nitre and terra foliata tartari will be 

 obtained. If the latter be separated by means of spirit of 

 wine, the vinegar may be got by the ordinary process. 



(2) Upon boiling the residuum over again with nitrous 

 acid, the same products are obtained. The oftener this 

 process is repeated, the less is procured of acid of sugar, 

 and at length no vestige of it is to be found. 



(3) If pure acid of sugar, completely formed, be boiled 

 with twelve or fourteen times its quantity of nitrous acid, 

 the former disappears, and the receiver is found to contain 

 phlogisticated nitrous acid, vinegar, aerial acid, phlogisticated 

 air ; and in the retort there remains a little calcareous 

 earth. 



(4) If acid of sugar be boiled with six times its quantity 

 of vitriolic acid, there are found in the receiver, vinegar, 

 phlogisticated vitriolic acid, aerial acid, and in the receiver 

 pure vitriolic acid. 



(5) By saturating the residuum of dulcified spirit of 

 nitre with chalk, there is formed an insoluble salt, which, 

 on being treated with vitriolic acid, yields a real acid of 

 tartar ; for, with vegetable alkali, it constitutes cream of 

 tartar. 



(6) If the liquor from which the tartarised lime 

 (tartareous selenite) was procured be evaporated, there 

 will remain a dark-coloured matter, which yields, on 



