DIFFICULTY IN DETECTING MINERALS. n 



deceiving as to their real value. For a long time the 

 chloride of silver deposits in Colorado were passed over 

 without their nature being known, and so were the car- 

 bonate of lead (carrying silver) unnoticed at Leadville, 

 which, through the discovery, in five years became a city of 

 30,000 inhabitants. Who would say how much per cent, 

 of nickel there is in a particular piece of the New Caledonia 

 hydrated silicate of nickel ore, or how much silver in the 

 Leadville ore, or what proportion of gold is likely to be in a 

 lump of copper pyrites or iron pyrites, unless he had made 

 each a special study ? Therefore it is just as well that a 

 person should be independent of the opinions of others 

 and, to a certain extent, of his own ; and, at the same time, 

 never grudge a few shillings or dollars in obtaining the 

 advice of a proper assayer. 



Let us now return to the original subject. Supposing 

 that a correct assay of the lode matter has been secured or 

 a rough one made, the prospector has still some items of 

 significant worth to consider before he commences to build 

 " castles in the air," or even continue development work. 

 He must find out if the ground is easily worked (for in one 

 locality though " sinking " through a soft ground may only 

 cost 2 a fathom, " sinking " through hard ground may cost 

 20 or more) ; if the ore to be smelted is refractory, or is 

 capable of concentration after sorting, before it is sent away 

 to the smelting or to the crushing and amalgamating works. 

 He must find out exactly the price of smelting or otherwise 

 treating the ore, taking into consideration such items as the 

 cost of labour, the freight of ore and fluxes as well as their 

 cost, the freight of the ores to the "works," &c. He must 

 take into account the proximity or distance off of both fuel 

 and water, as well as the obtainable quantity of each. Many 

 spots in Arizona and New Mexico exist where the working 

 of veins and alluvial diggings is impossible for the time 

 present, or retarded through the absence of creeks and 

 springs. He must remember that a lode running twenty 

 dollars' worth of metals to the ton may be of more value 

 than another running two hundred dollars not very many 

 miles off ; that a low-grade silver ore in one locality may be 



