APPE:tTDIX 487 



The sand consisted of colourless transparent quartz, not 

 unfrequently presenting the bright glassy lustre of broken 

 quartz crystal; the surfaces were, however, for the most part, 

 more or less dulled by abrasion. It contained a few flakes of 

 silvery mica, and, as Mr. Adams — to whom I handed a small 

 quantity for microscopical examination — informs me, an occa- 

 sional fragment of felspar. It is on the whole exceedingly 

 iine, 52 per cent, of the same passing a sieve of ninety meshes 

 to the linear inch; 16 per cent., one of seventy-five meshes; 

 15 per cent., one of sixty-six meshes, and 9 per cent., one of 

 fifty meshes, leaving a balance of 8 per cent, as rejected by 

 the latter. 



Subsequent to the foregoing examination, Mr. A. S. 

 Cochrane, of this Survey, handed me a specimen which he 

 collected, and which differs from the above in that it does not 

 appear to contain so much water, and the bituminous matter 

 partakes more of the nature of asphalt. At the temperature 

 of 65° P. it is quite hard, fragments may be chipped off with 

 a hammer, and it is reducible in a mortar to a non-coherent 

 pulverulent condition; at 100° P. it barely yields to pressure, 

 and is only slightly adhesive; at 150° P. it gives to the touch 

 and is somewhat sticky; at 300° P. it is quite soft, and may 

 be readily moulded. 



MALTHA OK MINEKAL-TAR. 



Prom the right bank of the Athabasca, about twelve miles 

 below its confluence with the Little Bed Eiver; collected by 

 Mr. A. S. Cochrane. 



This material also occurs at several other points farther 

 down the river, and is identical with that referred to in the 

 prefatory remarks. 



The sample in question had a pitchy-black colour in thin 

 layers, and by transmitted light, rich, dark reddish-brown. The 

 specific gravity at 60° P. was found to be 1.023; at this tem- 

 perature it ias the consistence of a soft extract, and will barely 

 flow; at 70° P. flows, but sluggishly, whilst at 100° P. it has 

 the consistence of treacle. 



As regards the utilization of these substances, the most 

 appropriate application of the former, and that for which it 

 would appear to be admirably adapted, would be for asphalting 

 ptirposes. It has one of the most important qualifications of 

 a good bituminous concrete, viz., intimate combination of the 

 mineral and organic constituents, and this in a degree which 



