226 SILVER LOCATIONS OF THUNDER BAT. 



by an attempt to work mining property with insufficient means, and on 

 too small a scale. The ore may yield a fair profit, but the production 

 is not sufficient to render the aggregate profit of much account. 

 Hence, if a lode begin to run poor, or the walls come together 

 for a time, or heavier machinery be required, or other difficulties 

 arise to cause a temporary stoppage, the works are too frequently 

 abandoned altogether. In estimating the value of the Thunder 

 Bay district, as a mineral region, it must not be forgotten that, 

 as regards climate, facility of access, cheapness of labour, etc., 

 the district possesses marked advantages over the other argentiferous 

 regions of this continent.| It should be remembered also, that the 

 amount of silver required to make a paying ore is very slight. In the 

 dressing of ordinary metallic ores, as those of lead or copper for example^ 

 an amount of metal equal to one or two per cent., is almost invariably 

 left in the waste slimes or tailings : whereas 1 per cent, of silver would 

 constitute an exceedingly rich product. If the silver in the ores of 

 this region were to average no more than the fourth of one per cent. 

 (pm)} the yield would be very large. Assuming this amount to be 

 found, and estimating the specific gravity of the vein matter (consisting 

 of quartz, calcite, blende, pyrites, &c.) at 3-0 only, each cubic fathom 

 would weigh a little more than 20 (American) tons, and would carry 

 1459 Troy ounces of silver, equivalent in value to about $1,955 (gold). 

 This is equal to nearly one hundred dollars per ton of ore^ whilst the 

 cost of raising and treating that quantity of material would probably in 

 DO case exceed ten or twelve dollars. The yield might be reduced,' 

 consequently, to the tenth of one per cent. (^-^), and the ore would 

 still give large returns. 



Until the nature of the ore at lower depths be definitely ascertained, 

 the question of its proper metallurgic treatment can be scarcely entered 

 into. If the silver be found to run chiefly^in the metallic form, a large 

 portion might be separated by simple mechanical processes, the tailings 

 being subsequently subjected to amalgamation. If, on the other hand, 

 the ore turn essentially to sulphide, without accompanying matters of 

 difficult mechanical separation, the amalgamating process, with previous 

 conversion of the ore into chloride, or a modification of the more modern 

 processes of Augustin or Von Patera, maybe found most suitable for the 

 extraction of the metal ; whilst, if much galena be present, the separa- 

 tion of the silver may be more economically effected, perhaps, by furnace 

 treatment. These points must necessarily be reserved for future con- 

 sideration. 



