Though the success of a particular day’s fishing may be a very uncertain matter, yet the local situation of the country being supposed, the general efficacy of industry in bringing a certain quantity of fish to market, taking the course of a year, or of several years together, it may, perhaps, be thought is certain enough; and it, no doubt, is so. As it depends more, however, upon the local situation of the country, than upon the state of its wealth and industry; as upon this account it may in different countries be the same in very different periods of improvement, and very different in the same period; its connection with the state of improvement is uncertain; and it is of this sort of uncertainty that I am here speaking.
In increasing the quantity of the different minerals and metals which are drawn from the bowels of the earth, that of the more precious ones particularly, the efficacy of human industry seems not to be limited, but to be altogether uncertain.
The quantity of the precious metals which is to be found in any country, is not limited by any thing in its local situation, such as the fertility or barrenness of its own mines. Those metals frequently abound in countries which possess no mines. Their quantity, in every particular country, seems to depend upon two different circumstances; first, upon its power of purchasing, upon the state of its industry, upon the annual produce of its land and labour, in consequence of which it can afford to employ a greater or a smaller quantity of labour and subsistence, in bringing or purchasing such superfluities as gold and silver, either from its own mines, or from those of other countries; and, secondly, upon the fertility or barrenness of the mines which may happen at any particular time to supply the commercial world with those metals. The quantity of those metals in the countries most remote from the mines, must be more or less affected by this fertility or barrenness, on account of the easy and cheap transportation of those metals, of their small bulk and great value. Their quantity in China and Indostan must have been more or less affected by the abundance of the mines of America.