FUSION OP BARYTES. 281 



M 2. That the anhydrous sulphate of lime, whether n a- sulphate of 

 tural or artificial, and the nonanbydrous sulphate calcined, lime > 

 contain the same proportions of lime and sulphuric acid ; 

 namely, 042 or 043 of lime, and 0*58 or 0*57 of acid, near- 

 ly as determined by Bergman. 



H 3. That the sulphate of bavytes is composed of at least sulphate of 



barvtes 

 0-33 sulphuric acid, and at most 0*67 of barytes, J » 



" 4. That the mean proportions of these two salts are: mean of both 

 0-425 of lime, and 0*575 of acid, for the sulphate of lime, se » 

 and o4>u7> of barytes, and 0335 of acid, for the sulphate of 

 barytes. 



" 5. And lastly, that in pure calcined sulphate of lead sulphate of 

 there are 0-69 of metal, 0-2(3 of sulphuric acid, -and 005 of , 

 pxigen." 



XII. 



Extract from a Letter of Mr. Geiilen to Mr. Descotils, 



on the Igneous Fusion of Barytes** 



Ji-T appears to me, that the French chemists are yet un*- igneous fusion 

 acquainted with the fusibijity of pure barytes by fire, which of baryte* 

 Mr. Bucholz discovered, and described in 1800, in the 2d 

 number of his Beitraege zur Erweiterung and Berichtigung 

 des Chimie. 



If pure barytes be heated in a platina or silver crucible, it succeeds the 

 liquefies in its water of crystallization. After this water is aqueous. 

 evaporated, it filters into fusion at a bright cherry red heat, 

 and- flows like an oil. On cooling, it becomes a gray mass, 

 radiated in its fracture, which, when powdered, redissolves 

 in water, heating more strongly than lime, and recrystal- 

 lizts in cooling. 



Mr. Bucholz, having h'therto prepared his pure barytes Does rot take 

 paly in Pelletier's method, did not know by experience, P lace Wlth ba - 

 that barytes did not melt when it has been prepared by the by decompo- 

 jlecomposition of the nitrate by tire; which it might have suioncf the 

 been expected- to do, but which 1 have never- seen take 



* Annaks de Chemie, Vol.LXlV. p. 168. 



place, 



