312 DOMAIN IV. TALCOUS. 



" Exposed to the blow-pipe, this stone melts 

 with difficulty into a greenish grey glass, semi- 

 transparent, which forms a globule, of the tenth 

 of a line at most. 



" It has therefore no resemblance with chlo- 

 rite, and, being obliged to give it a name, I have 

 called it laminar magnesian schistus. 



" We find enclosed in this stone some clusters 

 of crystals of the rayonnant, or strahlstein, which 

 I have described in the preceding paragraph; 

 and some detached crystals of octahedral iron. 

 It is found at Weysler Stoude, in the valley of 

 Urseren." 



MODE III. MICAREL SLATE. 



Distinctions. This has commonly been confounded with 

 mica slate, and uas the same general appear- 

 ance ; the spangles having however sometimes 

 more of the silver lustre, and in other examples 

 more of the unctuous cast of talc, than is ob- 

 servable in mica slate, where the magnesia is 

 strongly impregnated with iron. It has also 

 the usual adjuncts of talc, and seldom contains 

 garnet, or the other siderous substances, that are 

 found in mica slate. In decomposition, it some- 

 times forms plates or illinitions of steatite be* 



