ON THE PY ROT ART A ROUS ACID. 45 



a hot and pungent taste, and a foliated form, like acetate of 

 potash. 



3. This salt precipitated the nitrates of mercury and of Precipitates 

 silver in white scales; but it precipitated the solution of 

 acetate of lead also, which acetate of potash does not. 



4. Exposed to the fire it swelled up, and was carbo- 

 nized. 



5. Distilled with diluted sulphuric acid by a gentle heat, Distilled with 

 it turned black, and toward the end of the process yielded a su p 

 white sublimate, which adhered to the whole surface of the 



retort in the form of scales. The liquid, that came over 

 before the sublimate appeared, hud a very decided acidity, 

 which was not owing to the sulphuric acid employed; but 

 it had only a very slight smell of vinegar. 



6. This process, the distillation of the salt formed by the Singular phe- 

 pyrotartarous acid and potash, afforded a singular appear- nomea<m * 

 ance. The acid liquid just mentioned contained at the bot- 

 tom a large globule of another liquid, with a slight yellow 



tinge, that rolled about when the vessel was moved without 

 mixing with the liquid containing it. It resembled phos- 

 phorus melted at the bottom of water. As it was night, 

 Messrs. Fourcroy and Vauquelin stopped the vessel very 

 close, in order to examine it more accurately the next day: 

 but in twelve hours it was not to be seen, the heavy globule 

 having mixed with the other liquid during the night. 



7. Thie retort being cut, the crystals were separated as Crystals pro- 

 completely as possible, and exhibited the following proper- duced - 

 ties. 



a. Their taste was extremely acid. Their proper- 



b. They readily melted, and evaporated in white fumes, ties * 

 when placed on a heated substance. 



c. They dissolved copiously in water, and crystallized 

 again by spontaneous evaporation. 



d* Their solution did not precipitate that of acetate of 

 lead, or that of nitrate of silver, but it precipitated nitrate 

 of mercury. However, some time after this .acid had been 

 mingled with a solution of acetate of lead, needly crystals 

 were found it arranged in plumes. 



e. The solution of this acid partly saturated with potash 

 does not furnish an acidule as the tartar© us acid does, but 



it 



