390 On Metallic Minerals. 



a hydrate of magnesia, but upon a closer examination it 

 'appears to agree better with that variety of hydrate of 

 aHumine, called heuzenite by Cleaveland. It is just as 

 likely however, to be one of the numerous family of clays, 

 a bole, or lithomarge, for instance. It does not form a 

 paste with water, and is not easily reduced to an impalpable 

 powder. 



A calcareous spar of the lustre of satin spar, and also 

 sometimes of the same structure is found in thin veins in 

 the rock. Its usual structure, however, is laminar, and 

 the laminae appear to be arranged diagonally as regards 

 the sides of the vein, having their polished faces striated in 

 narrow blue bands like the water lines on paper, parallel to 

 the sides of the vein in which direction there are probably 

 cleavages although none could be obtained. 



A species of potstone or foliated soapstone is obtained 

 under the same circumstances. 



Hexagonal crystals of silver mica are found imbedded. 



A beautiful enamel coating often fluted and of a j)urple, 

 a green, or a reddish colour was seen upon the surface of 

 some of the talcose schist forming the sides of the veins in 

 which the supposed hydrate of allumine was obtained, also 

 upon the satin spar. Advantage has been taken of the fall 

 and of the rocky elevation on either side of it, to construct 

 a dam and to establish a saw mill. On the left side of the 

 saw mill and of the river, the serpentine rock is seen 

 forming a perpendicular scarp. It is composed of the pre- 

 cious variety of serpentine, and appears to form a thick bed 

 in the talcose schist. On the ujjper surface of this serpentine 

 is seen in patches a thin white compact coating of a mineral, 

 which bears some resemblance to the minei'al before 

 described, but it is found to effervesce and dissolve very 



