which have since been occasionally imposed upon particular sorts of goods, have, with a few exceptions, been laid altogether upon importation. The greater part of the ancient duties which had been imposed upon the exportation of the goods of home produce and manufacture, have either been lightened or taken away altogether. In most cases, they have been taken away. Bounties have even been given upon the exportation of some of them. Drawbacks, too, sometimes of the whole, and, in most cases, of a part of the duties which are paid upon the importation of foreign goods, have been granted upon their exportation. Only half the duties imposed by the old subsidy upon importation, are drawn back upon exportation; but the whole of those imposed by the latter subsidies and other imposts are, upon the greater parts of the goods, drawn back in the same manner. This growing favour of exportation, and discouragement of importation, have suffered only a few exceptions, which chiefly concern the materials of some manufactures. These our merchants and manufacturers are willing should come as cheap as possible to themselves, and as dear as possible to their rivals and competitors in other countries. Foreign materials are, upon this account, sometimes allowed to be imported duty-free; spanish wool, for example, flax, and raw linen yarn. The exportation of the materials of home produce, and of those which are the particular produce of our colonies, has sometimes been prohibited, and sometimes subjected to higher duties. The exportation of English wool has been prohibited. That of beaver skins, of beaver wool, and of gum-senega, has been subjected to higher duties; Great Britain, by the conquests of Canada and Senegal, having got almost the monopoly of those commodities.
That the mercantile system has not been very favourable to the revenue of the great body of the people, to the annual produce of the land and labour of the country, I have endeavoured to show in the fourth book of this Inquiry. It seems not to have been more favourable to the revenue of the sovereign; so far, at least, as that revenue depends upon the duties of customs.