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times its original size, and shooting out long cylinders or 

 prisms of a worm-like appearance. 



The following is a description of the mineral operated upon. 

 This mineral occurs in small thin scales, having an olive green 

 color when seen by reflected light and an apple green color by 

 transmitted light. These scales are imbedded in a soft magne- 

 sian rock resembling decomposed talcose rock, but which prob- 

 ably consists of the decomposed particles of Vermiculite mixed 

 with various earthy and ferruginous matters. 



The scales of Vermiculite are rarely more than a sixth of an 

 inch in diameter, and although they are apparently irregular 

 prisms, are not well defined on the lateral planes. They split 

 easily into very thin laminae like talc, and are flexible and not 

 elastic. They have an unctuous feel when rubbed between the 

 fingers, but this character is not so marked as in talc. 



Their lustre is pearly and somewhat greasy. Color, as before 

 stated, olive green by reflected light, and apple green by trans- 

 mitted light. Thin scales are tianslucent and sub-transparent. 

 Hardness a little above 1. of the scale of Mohs. Specific gravity 

 of the dried mineral, according to Crossley, 2.756. 



A scale of the mineral, heated before the blowpipe, instantly 

 swells and shoots out into a long cylinder or prism curling like 

 a worm. The sides of this vermiform mass are marked by 

 transverse divisions from separation of the laminae of the mineral, 

 and the scale is found to have increased to from fifty to nearly 

 one hundred times its original thickness. On raising ihe tem- 

 perature to redness the mineral glows strongly and is found, after 

 cooling, to have changed its aspect, having now a perfectly silver 

 white color with a strong pearly lustre. A scale held in the forceps 

 is readily melted before the blowpipe into a bottle green glass. 

 With Carbonate of Soda it melts into an opaque brownish green 

 bead. 



With Borax it dissolves into a clear yellow glass which be- 

 comes colorless on cooling. In the reducing flame the color 

 assumes a greenish tint. With salt of Phosphorus it dissolves 

 readily, imparting a yellow color to the bead while hot, and 

 becomes colorless on cooling. The bead becomes white and 

 slightly opaque from separation of the silica. Heated in a glass tube 

 the mineral quickly exfoliates into long prisms, giving out water, 



