1865.] PERLEY — GOLD .MIXING IN NOVA SCOTIA. 205 



found to vary greatly, sometimes gradually thinning out to a 

 mere thread, and then increasing in size as a greater depth is 

 reached. They are often split-up into two or more branches, or 

 are greatly enlarged by the junction of cross-veins. Neither do 

 the veins dip with any degree of regularity, many of them having 

 three or four rates of dip, which renders the sinking of shafts a 

 troublesome and oftentimes an expensive matter ; for the shafts 

 are sunk vertically through the earth to the bed-rock, and 

 then generally driven with the vein, and always on the lower or 

 foot-wall side. Faults occur in most veins, owing no doubt to 

 dislocations of the strata ; and instances are known where the vein 

 has been cut entirely off, and thrown for some feet. 



It is generally supposed that auriferous veins present the richest 

 ore at the surface, and decrease in the value of their yield with the 

 depth, until at depths ranging from one to two hundred feet they 

 no longer pay for working. This opinion is countenanced by the 

 highest French and English authorities, and is supported by a wide 

 class of facts. In Australia very large sums were spent in deep 

 sinking on veins which were productive at the surface, but when 

 certain depths were reached they proved barren and unprofitable. 



In 1859 and 1 860, after the quartz veins of Victoria (Australia) 

 had been for some time neglected, the received opinion that auri- 

 ferous veins diminished in value with their depth was disregarded, 

 and, judging from a few exceptional cases where veins had paid at 

 depths of from two to four hundred feet, those veins that had 

 proved rich at the surface or within a depth of one hundred feet, 

 were again opened and active operations carried on. But it was 

 found that the rule held good ; and it is boldly stated, that there 

 are not six veins in the colony of Victoria (in 1860) from which 

 a sufficient quantity of gold had been extracted at a depth of four 

 hundred feet to pay the cost of extraction. Sir Roderick Murchison 

 has stated, that the rule prevails in "auriferous countries " that the 

 working of gold-bearing quartz is not remunerative excepting near 

 the surface, the ore being concentrated in the upper parts of the 

 lodes." 



Whether this rule will hold good in Nova Scotia still remains to 

 be proved. So far, varied success has been met with in different 

 shafts, which have been sunk to depths reaching from eighty to 

 one hundred feet. At Waverley a shaft is now down one hundred 

 and eighty-five feet, and the quartz obtained at that depth proves 

 richer than that obtained at or near the surface. 



