in which San Franciscan leather was exchanged for the matting produced on the island. Let it be supposed that in San Francisco leather can be made for one-fifth of the sacrifice of labour and capital that is necessary to its production on the island; but that matting can be made on the island at only a slightly greater sacrifice of labour and capital (say one-tenth more) than at San Francisco. Then, if there is no trade between the two countries, it follows that these commodities exchange for each other at different rates of value in the two countries. Leather being so very difficult to produce in the island, exchanges there at a very high value compared with matting: a pair of boots, we will say, would exchange in the island for forty yards of matting. But at San Francisco, although both matting and leather can be produced with less capital and labour than on the island, the San Franciscans have a much greater advantage over the islanders in the production of leather than in the production of matting; the comparative value of the two commodities is therefore very different at San
