which took place, during the action of heat in the moist way, 

 were not minutely examined. 



Mercury. Moist proto-carbonate of mercury dissolved in the 

 acid forming a salt not quite neutral, crystallizing feebly in the 

 air, white, of a metallic taste, not deliquescent, and decomposed 

 with various phsenomena by heat. By re-solution in water or 

 alcohol, and heat, a sub-salt of a yellow colour was formed. 



The moist liydrated per-oxide of mercury also dissolved in the 

 acid, forming an acid solution, which by evaporation gave a 

 yellowish dehquescent salt, decomposed by heat, burning in the 

 air, and entirely volatile. 



3. Analysis of the Acid and Salts. 



When solution of the pure acid was subjected to the voltaic 

 battery, oxygen and hydrogen gases were evolved in their pure 

 state : no solid matter separated, but the solution became of a, 

 deep-yellow colour at the positive pole, occasioned by the evo- 

 lution of free sulphuric acid, which re- acted upon the hydro- 

 carbon. A solution of the barytic salts gave similar results. 



The analytical experiments upon the composition of this acid 

 audits salts were made principally with the compound of baryta. 

 This was found to be very constant in composition, could be 

 obtained anhydrous at moderate temperatures, and yet sustained 

 a high temperature before it suffered any change. 



A portion of the pure salt was prepared, and dried for some 

 hours on the sand-bath, at a temperature about 212°. Known 

 weights were then heated in a platinum crucible to dissipate and 

 burn off the combustible matter ; and the residuum being moist- 

 ened with sulphuric acid to decompose any sulphuret of barium 

 formed, was heated to convert it into a pure sulphate of baryta. 

 The results obtained were very constant, and amounted to 

 41-714 of sulphate of baryta per cent, of salt used, equivalent to 

 27*57 baryta per cent. 



Other portions of the salt were decon^posed, by being heated 

 in a flask with strong nitro-muriatic acid, so as to liberate the 

 sulphuric acid from the carbon and hydrogen present, and yet 

 retain it in the state of acid. Muriate of baryta was then added, 

 the whole evaporated to dryness, heated red-hot, washed with 

 dilute muriatic acid to remove the baryta uncombined with 

 sulphuric acid, and the sulphate collected, dried, and weighed. 

 The results were inconstant ; but the sulphate of baryta obtained 

 always much surpassed that furnished by the former method. 

 Judging from this circumstance that the sulphuric acid in the 

 salt was more than an equivalent for the baryta present, many 

 processes were devised for the determination of its quantity, 

 but were rejected in consequence of difficulties and imperfec- 

 tions, arising, principally, from the presence and action of so 



p 2 



