VALUE OF A MINING CLAIM. 



" assays " payably, simply because his money and time are 

 of too much worth to admit of the expensive and sometimes 

 apparently endless labour involved in developing work. A 

 capitalist may risk some of his quickly amassed gains in 

 following up research in the hope of some day increasing 

 his capital, although he quite understands how thoroughly 

 the game is a chance one ; but the ordinary miner should 

 avoid uncertainties much more than he usually does. 



That a lode carries gold and silver or any other valuable 

 metal in some form or other, is not sufficient data to lean 

 upon in the estimation of its worth. Oftentimes the gold, 

 for instance, is distributed in the form of very fine powder 

 invisible to the eye and covered with a rusty film (due to 

 sulphides or arsenides, oxide of iron or manganese, and 

 sometimes to sulphate of copper and iron) ; and in conse- 

 quence, though the " assay " may be favourable, the extrac- 

 tion of the precious metal from the ore by the amalgama- 

 tion is not satisfactory, as the mercury " sickens " or 

 " flours." Again, the value of a body of ore, though it may 

 be rich in precious or valuable metals, depends in a measure 

 upon the nature of the other constituents, especially when 

 the ore has to be smelted. Antimony or arsenic, in not very 

 great quantities either, may render an otherwise valuable 

 ore useless so far as profitable smelting is concerned. Before 

 digging operations are commenced, the pieces of rock from 

 the lode should be examined, and, if such is possible, by a 

 reliable assayer, who, if he suspects the presence of precious 

 metals, will, by scorification or melting in 3, crucible, and 

 afterwards by cupellation method, determine the amount of 

 gold and silver per ton of a similar rock, and, without 

 undertaking a careful quantitative analysis of the other 

 associated metallic compounds, will, from the slag in the 

 scorifier or crucible and colour or appearance of the bone 

 ash cupel after the operation is concluded, be able to judge 

 approximately what proportions of the metals copper, iron, 

 lead, antimony, zinc, &c., are mixed with the others. It is 

 always the wisest plan to obtain a proper assay before 

 development work is entered on. Unfortunately, this is not 

 an easy matter in out-of-the-way places. To assay correctly 

 means a course of training ; for this reason the author can- 



