[ 22 ] [Book VI. 



CHAP. V, 

 VITRIOLIC SALTS. 



Glauler*s Salt ; bcnu de compofed J Solution of it left to ccol cryfta.liix.cs 

 cii being fnaken.T-Vitriolated Tartar. Vilriolated Ammoniac. 



THE firft fubftances of this kind which challenge 

 our attention, are Glauber's fait and vitriolated 

 * tartar, or as they are denominated in the new chemical 

 nomenclature, fulphat of foda, and fulphat of pot afh. 

 The former of thefe neutral falts is compofed of the 

 vitriolic acid, combined with the mineral alkali j and 

 the latter of the fame acid with the vegetable alkali. 

 They both have a faline bitternefs. By heat their ingre- 

 dients may be raifed into vapour, but no one fimple 

 fait will feparate them, as no acid has a ftronger at- 

 traction for the alkali than the vitriolic, nor any alkali 

 a ftronger attraction for the vitriolic acid than the 

 fixed. Dr. Stahl propofed the effecting of this fepara- 

 tion as a problem. He knew how to folve it, and it 

 was afterwards done by a double elective attraction. 

 Another more curious method is this : take Glauber's 

 fait or vitriolated tartar, melt the fait in a hot cruci- 

 ble, and add to it firft a quantity of charcoal, which 

 has a ftronger attraction for the oxygen of the vitriolic 

 acid than the latter has for the alkali. Thefe being 

 expofed to heat, the charcoal in part difappears, and 

 the mixture acquires a deep red colour. If the matter is 

 poured out, we find it to be an bet>arjulf burls, or liver 

 of fulphur, the charcoal having carried off with it the 

 oxygen in the form of carbonic acid gas. 



GLAUBER'S SALT is more fufible than vitriolated 



tartar, melting in a moderate degree of red heat. The 



folution of Glauber's fait forms into columnary cryftals, 



p which, 



