1826.] SulpJiO'Naphthalic Acid. 191 



description), when obtained by the slow evaporation of the satu- 

 rated solution, formed tufts, which were imperfectly crystalline. 

 When drops were allowed to evaporate on a glass plate, the 

 crystalline character was also perceived ; but when the salt 

 was deposited rapidly from its hot saturated solution, it ap- 

 peared in the form of a soft granular mass. When dry, it was 

 white and soft, not changing in the atmosphere. It was rea- 

 dily soluble in water and alcohol, but was not affected by ether. 

 Its taste was decidedly bitter. When heated in the air on 

 platinum foil it burnt with a bright smoky flame, like naphtha- 

 line, sending flocculi of carbon into the atmosphere, and leaving 

 a mixture of charcoal, sulphuret of barium, and sulphate of 

 baryta. 



After being heated to 212 for some time, the salt appeared 

 to be perfectly dry, and in that state was but very slightly 

 hygrometric. When heated in a tube, naphthaline was evolved ; 

 but the substance could be retained for hours at a temperature 

 of 500 F. before a sensible portion of naphthaline had sepa- 

 rated : a proof of the strength of the affinity by which the 

 hydrocarbon was held in combination. When a higher tempe- 

 rature was applied, the naphthaline, after being driven off, 

 was followed by a little sulphurous acid, a small portion of 

 tarry matter, and a carbonaceous sulphate and sulphuret were 

 left. 



This salt was not affected by moderately strong nitric or 

 nitromuriatic acid, even when boiled with them ; and no pre- 

 cipitation of sulphate took place. When the acids were very 

 strong, peculiar and complicated results were obtained. When 

 put into an atmosphere of chlorine, at common temperatures, 

 it was not at all affected by it. Heat being applied, an action 

 between the naphthaline evolved, and chlorine, such as might 

 be expected, took place. 



When a strong solution of the pure acid was poured into 

 a strong solution of muriate of baryta, a precipitate was formed, 

 in consequence of the production of this salt. It was re-dis- 

 solved by the addition of water. The fact indicates that the 

 affinity of this acid for baryta is stronger than that of muriatic 

 acid. 



The second, or glowing salt of haryta, was obtained in small 

 crystalline groups. The crystals were prismatic, colourless, 



