The Wealth of Nations by Part 4 Chapter 7 Page 70

Rum is a very important article in the trade which the Americans carry on to the coast of Africa, from which they bring back negro slaves in return.

If the whole surplus produce of America in grain of all sorts, in salt provisions and in fish, had been put into the enumeration, and thereby forced into the market of Great Britain, it would have interfered too much with the produce of the industry of our own people. It was probably not so much from any regard to the interest of America as from a jealousy of this interference that those important commodities have not only been kept out of the enumeration, but that the importation into Great Britain of all grain, except rice, and of salt provisions, has, in the ordinary state of the law, been prohibited.

The non-enumerated commodities could