makes a greater demand for commodities possible.
As the shipwrecked sailors on the island gradually got cleverer in the work they had undertaken to do, their labour became more productive; and directly their labour was more productive a greater number of things were bought and sold, or exchanged. In other words, when a greater amount of wealth was produced, there was a corresponding increase in the demand for, and the supply of, commodities.
Two or three of the sailors were fortunate enough to find a bag of wheat only slightly damaged by the salt water. As may be imagined, it was most carefully dried in the sun, and every grain was valued much more than if it had been made of solid gold. A favourable piece of ground was looked out; it was then dug by the men who had found the wheat, and when what they all thought the best season for sowing had arrived, the precious grains were carefully deposited in the rich soil. When the first green blades appeared above the ground there was a general feeling of re-
