much more extensible by cheapness, that if England had no commodity but cloth which Germany would take, the demand of England would force up the terms of interchange to 10 yards of cloth for only 16 of linen, so that England would gain only the difference between 15 and 16, Germany the difference between 16 and 20. But let us now suppose that England has also another commodity, say iron, which is in demand in Germany, and that the quantity of iron which is of equal value in England with 10 yards of cloth, (let us call this quantity a hundredweight) will, if produced in Germany, cost as much labour as 18 yards of linen, so that if offered by England for 17, it will undersell the German producer. In these circumstances, linen will not be forced up to the rate of 16 yards for 10 of cloth, but will stop, suppose at 17; for although, at that rate of interchange, Germany will not take enough cloth to pay for all the linen required by England, she will take iron for the remainder, and it is the same thing to England whether she gives a hundredweight of iron or 10 yards of cloth, both being made at the same cost. If we now superadd coals or cottons on the side of England, and wine, or corn, or timber, on the side of Germany, it will make no difference in the principle. The exports of each country must exactly pay for the imports; meaning now the aggregate exports and imports, not those of particular commodities taken singly. The produce of fifty days' English labour, whether in cloth, coals, iron, or any other exports, will exchange for the produce of forty, or fifty, or sixty days' German labour, in linen, wine, corn, or timber, according to the international demand. There is some proportion at which the demand of the two countries for each other's products will exactly correspond: so that the things supplied by England to Germany will be completely paid for, and no more, by those supplied by Germany to England. This accordingly will be the ratio in which the produce of English and the produce of German labour will exchange for one another.
