1820.] a new Variety of Calestine. 285 



platinum crucible, 54*75 gr. Hence it follows that the whole 

 sulphate of strontian contained in the mineral amounts to 109'5 gr. 

 (F.) The portion of salt which did not dissolve in alcohol was 

 dissolved in water, and the solution evaporated till the salt was 

 obtained in crystals. These crystals were tables, and possessed 

 the characters of muriate of barytes. Being dissolved in water, 

 and mixed with the Hquid from which the sulphate of strontian 

 had been separated by filtration, a precipitate of sulphate of 

 barytes fell down, which, when washed, dried, and heated to 

 redness, weighed 39*25 gr. 



From the preceding experiments, it appears that the 150 gr^ 

 of the mineral were composed of 



Ferruginous alumina (D) 0*32 



Sulphate of strontian (E) , 109*50 



Sulphate of barytes (F) 39*25 



149*07 

 Loss 0*93 



150*00 

 Consequently the constituents in 100 parts of the mineral are as 

 follows : 



Ferruginous alumina 0*213 



Sulphate of strontian 73*000 



Sulphate of barytes 26*166 



99*379 

 Loss 0*621 



100*000* 

 This caelestine is remarkable for the great proportion of sul- 

 phate of barytes which it contains. I have never before heard 

 of any caelestine containing more than two or three per cent, of 

 this salt. This circumstance induced me to repeat the analysis 

 again ; but I obtained almost exactly the same result. We 

 must, therefore, as I observed before, consider this mineral as 

 constituting a new variety of caelestine hitherto unknown. 



These remarks apply likewise to the weathered caelestine in the 

 third bed. I analyzed it in the same way as the crystallized 

 caelestine, and obtained the following result : 



Alumina 1 *00 



Sulphate of strontian 24*00 



Sulphate of barytes 74*66 



99*66 

 Loss 0*34 



100*00 



* This is almost rxaclly seven atoms of sulphate of strontian to tiro atoms of rul- 

 phale of bardlet. Hence it is probable that the mineral it a cliemicaiconpound, — T. 



