MODE II. TALCOUS SLATE. 



" As then this schistus results from the assem- 

 blage of diffeiji6nt stories, all of the talcous class, 

 I call it composite magnesian schistus. 



" 1917. The collection that Mr. Struve sent 

 to me contains a stone, with a label, which sig- 

 nifies that Mr. Werner had named it an indis- 

 tinct variety of chlorite slate. Perhaps in this 

 instance, as in the former, Mr. Werner assigned 

 the name from specimens different from what I 

 received. In fact these are still farther removed 

 from chlorite. 



" The rock before me, and of which I possess 

 two large pieces, is of a black inclining to green. 

 Its fracture is laminar, with plates often undu- 

 lated, very thin, separable into very fine flakes, 

 the direction of which varies in different parts of 

 the same piece. This fracture is indifferently 

 bright, and of a lustre inclining to the unctuous, 

 as well as its touch. It is translucent on its 

 edges, to the thickness of half a line; the very 

 fine laminae appear white and colourless : but 

 those which are thicker, when looked through, 

 appear of a beautiful leek green. 



" This stone is soft, and may be scratched 

 even with the nail ; the streak being of a whitish 

 grey, but little brilliant. Moistened by the 

 breath, it exhales a strong earthy smell. Its 

 specific weight is 2,905. 



