the Waters of a Salt Spring in Hue I Set on Mine. 31 





Unaltered clay-slate. 



Rock in vicinity of cross- 

 course. 



I- 



11. 



I. 



ir$7l> 



45-85 



16-60 



10-59 



trace 



116 



2-68 



6-94 



•92 

 trace 

 5-64 



•78"! =-146 



•68JFeS 2 



•76 

 trace 



II. 



6-84 



4597 



16-78 



10-72 



trace 



112 



2-68 



6-87 



•78 

 trace 

 5-53 



•801 =-150 



•70 J FeS 2 



•74 

 trace 



Water* 



3-13 a 

 67-78 



9-60 



509 

 trace 



127 



2-62 



3-48 



2-45 



4-46 

 •361 =-68 

 •32/FeS 2 



310 



67-87 

 9-52 

 4-96 

 trace 

 114 

 254 

 337 

 2 30 



4-32 

 •32 1 =60 



•28JFeS 2 



Silica 



Alumina 



Ferrous oxide 



Ferric oxide 



Manganous oxide. 

 Lime 



Magnesia 



Potassa 



Lithia 



Soda 





Iron 



Sulphuric acid ... 

 Chlorine 







100-56 



99-72 



99-47 99-53 



Thin sections of the clay-slate situated at a distance from the 

 cross-course are seen under the microscope to consist of bands 

 of transparent granular quartz alternating with layers of similar 

 quartz, through which a transparent, dichroic, pinkish-brown 

 mineral is thickly disseminated in the form of imperfectly de- 

 fined eloo gated crystals. The outline of these, of which the di- 

 mensions of the largest are y'ooo x To o o °f an i ncn > * s s0 ""re- 

 gular, and they are so crowded and interlaced, that it is impos- 

 sible to determine their crystalline form; they are, however, 

 believed to be hornblende. 



When examined with an inch objective, the mass, in addition 

 to numerous crystalline bodies, appears to be full of a brown 

 dust, arranged in approximately parallel bands, which much 

 diminish the transparency of those portions of the sections in 

 which it most plentifully occurs. By the aid of a power mag- 

 nifying 510 diameters, this dust is resolved into crystalline tufts 

 of a dark colour and hornblendic appearance. Dendritic patches 

 and crystals of iron pyrites are disseminated throughout the 

 rock; and some of the veins by which it is traversed enclose well- 

 defined crystals of both chlorite and hornblende. 



The altered rock in the immediate vicinity of the cross-course 

 is seen to be composed of closely matted prisms of brown horn- 

 blende enclosing pale green crystals of actinolite. It also con- 

 tains a few crystals of quartz, and iron pyrites in the form of 

 minute cubes. 



* a lost "94 per cent, in the water-bath, and b 1*55 per cent. 



