14 THE ROYAL SOCIErY OF CANADA 



inclined i^hnfts and adits. They wt-ie found to show thice well-defined 

 zones as follows in descending order: fiist, a zone of oxidation and 

 leaching; second, a zone of secondar)^ sulphide enrichment; third, a 

 zone of poor, low-grade primary ore. 



One of these veins was being opened ])y Mr. Daulton by a shaft 

 following its dip. The vein matter was quartz, mixed with galena and 

 other sulphides, with considerable loose ochreous material near the 

 surface. A few feet below the surface, and within the zone of oxida- 

 tion, I found small irregular masses, up to the size of a walnut, of a 

 brown translucent resin-like substance which, on being taken into the 

 warm hand or out into the air, quickly flev;" into small sharply angular 

 pieces. So readily did tne substance brealc up that it was found quite 

 impossible to carry away clean coherent masses of any considerable size. 

 Those which I did collect and cairy away were put into the hands of 

 the late Professor B. J. Harrington of McGill University, Montreal, for 

 determination and desc^-iption, but his ill health and subsequent death 

 prevented the completion of his examinations. The work was subse- 

 quently put into the hands of Professor Graham, and most of the ma- 

 terial which remained in my possession has been used l:)y him in making 

 the examinations, the results of which are given below. 



Cheynical and Physical Properties. By R. P. D. Graham. 



The mineral, which is nearly black in colour with a brownish tinge, 

 occurs as irregular concretionary masses embedded in a pale yellowish 

 brown earthy material resembling ochre; the lustre is vitreous inclin- 

 ing to pitchy. As seen in mass, it appears opaque, but fine splinters 

 examined imder the microscope transmit light of a deep brown to yel- 

 lowish brown colour depending on their thickness; they are clear and 

 homogeneous, but isotropic, the substance being amorphous. The 

 hardness is between 2 and 3 and the streak brownish yellow. The 

 mineral is exti'emely brittle, breaking sharply with a smooth to con- 

 choidal fracture. A remarkable and distinctive property is observed 

 when fragments are immersed in water: these immediately commence 

 to fly to pieces with a crackling sound and the disengagement of gas, 

 very much after the manner of aquacreptite which it further resembles 

 in general appearance. This property was first o])served during the 

 determination of the specific gravity by the pycnometer method, and 

 owing to this it is impossible to arrive at any exact value for the specific 

 gravity, since the density becomes progressively higher as more and 

 more gas is liberated. In the determination made, the specific gravity 

 was found to be 2.65 immediately after immersion in the water, and 

 it had risen to 2.86 after allowing the bottle to stand for 30 houis. 



