^ Seyhert^s Analysts of the Jilaclureite. 330 



L 



orated to a dry saline mass, and the residue was exposed 

 to a red heat, to expel (he arnnioniacal salts; the fixed salt 

 weighed 0.12 grammes ; when treated willi water it dissol- 

 ved, leaving 0.02 grammes of insohibic matter, the filtercJ 

 ^^ohition, on being slowly evaporated, furnished very minute 



'"^regular cubes, which, when dried and exposed to the at- 



mosphere, did not deliquesce ; fh<^y were dissolved in wa- 

 ter, and the concentrated solution when tr(^ated with the 

 Jnunate ofplatirjaj gave a yellow precipitate of muriate of 

 potash arid platina. which was \evy abundant in proportion 

 to the quantity of salt employed ; the alcali thus proved to 

 be potash, and the 0.10 grammes muriate of potash arc 

 equivalent to 0.0632C grammes of potash on three grammes. 

 firSJOS per 100. 



The products of this analysis arc as follows : 



Per 100 Parts, 

 A. Water, r - 00.6CC 



K Silica, - - 31.000 



C. Per oxide of Iron, 03.000 



D. Magnesia, - 56.000 

 K, Potash, . ' 02.108 



92.774 

 100.000 



7.226 Loss. 



^^rom the preceding result I was satisfied, that this mine- 



*'^1 must contain some other constituent than t^iose which 



'had detected in it, and on comparing the oxyg6n of the si- 



hca with that of the magnesia, it appeared very probable, 



that it might be an acid. I searched for boric acid without 



success. To discover Fluoric acid, I proceeded in the 



'Ollowing manner, 1st, a portion of the pulverized mineral 



^'as heated with an excess of sulphuric ^Id, and a piece of 



K'ass was exposed to the fumes, which w^ere disengaged from 



the mixture, but it exhibited no signs of corrosion ; from 



}ni3 experiment, I could not conclude the absence of fluor- 



jc acid, for the silica contained in the mineral would proba- 



^^/ have been sufficient to saturate it, and thereby pre- 



^^^it its action on the glass. 2. Three grammes of the 



pulverized mineral were fused, during thirty minutes, in a 



