194 On Sulphuric Acid and Naphthaline. [1826. 



water or alcohol, and heat, a subsalt of a yellow colour was 

 formed. 



The moist hydrated peroxide of mercury also dissolved 

 in the acid, forming an acid solution, which by evaporation 

 gave a yellowish deliquescent 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 evolution of free 

 sulphuric acid, which reacted upon the hydrocarbon. A solu- 

 tion of the barytic salts gave similar results. 



The analytical experiments upon the composition of this acid 

 and its 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 of about 212. Known 

 weights were then heated in a platinum crucible to dissipate 

 and burn off the combustible matter ; and the residuum being 

 moistened 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 decomposed by being heated 

 in a flask with strong nitromuriatic 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 ob- 

 tained 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 pre- 

 sent, many processes were devised for the determination of its 

 quantity, but were rejected in consequence of difficulties and 



