Another cause will necessarily act on the production of silver, and that is the very abundance of gold. When silver is found to be more in demand, fresh activity will ensue, both in reopening old galleries, which have been closed as not sufficiently remunerative, and in pushing on the work in those actually in operation. If the mines, feeding the present supply, are becoming exhausted, and other sources are not forthcoming, in a few years silver will reach the price of gold, or the value of gold will descend to that of silver; but as the limits of silver working are but the price of labour, the power of machinery, and the application of science, so, every increase in the quantity of gold which is not caused by accidental circumstances, or by an extraordinary demand, must produce a corresponding increase in the production of silver. Is not this a fact which we have been witnessing since 1850? Who can venture to affirm that Californian gold has had no influence in stimulating the workings of silver in Mexico and Chili? Besides this, the extraction of gold is generally accompanied with a production of silver. Silver mines are not always auriferous, and the richest in gold contain but a small quantity of it, but gold mines are almost always argentiferous. The proportion of silver in a “nugget” of gold is about ⅛th in California, ¹⁄₁₀th in Siberia, and ⅕th in New South Wales. So that for every [173]four kilogrammes of gold in Australia, there is about one of silver. This is an important fact resulting from chemical analysis. The production of silver is in the course of increase. Will that of gold be kept up? It is reasonable to entertain considerable doubt on this point. In Siberia we have seen it retrograde since 1847. The extraction appears stationary--perhaps rather on the decrease in California. Australia alone, with gold fields yet unexplored, appears likely to produce much more than heretofore. Auriferous strata may be discovered elsewhere, and add to the general stock. Combining these various circumstances, we incline to the opinion that the quantities now forming the annual production of gold will not be diminished for a certain number of years; but when the miners have exhausted the gatherings from the alluvial deposits, and it becomes necessary to seek the golden ore in the rocks and mountains, in which nature appears during the various revolutions and convulsions of the world, to have deposited it; then the working of the mines will depend upon the amount of capital and the degree of science, which may hereafter be brought to bear on that description of enterprize.