#17. Land or Source of Materials.# The word #production# is a very good one; it means #drawing forth# (Latin, _pro_, before, and _ducere_, to draw), and it thus exactly expresses the fact that, when we want to create wealth, we have to go to some piece of land, or to some lake, river, or sea, and draw forth the substance which is to be made into wealth. It does not matter whether the material comes from the surface of the earth, or from mines and quarries sunk into the earth, or from seas and oceans. Our food mostly grows upon the land, as in the case of corn, potatoes, cattle, game, &c.; our clothes are chiefly made of cotton, flax, wool, skins, raised in like manner. Minerals and metals are obtained by sinking pits and mines into the crust of the earth. Rivers, lakes, seas, and oceans are no slight source of wealth: they yield food, oil, whalebone, sealskin, &c. We cannot manufacture any goods unless we have some matter to work upon; to make a pin we must get copper, zinc, and tin out of mines; a ribbon requires the silk and the dye materials; everything that we touch, and use, and eat, and drink, contains substance, so that we must always begin by finding a supply of the right sort of materials. Commonly, too, we want something more than matter; we want force which shall help us to carry and work the raw material. People naturally wish to avoid tiring themselves by labouring with their own arms and legs, and so they make windmills to grind corn, ships to carry goods, steam-engines to pump water and to do all sorts of hard work. From the earth, or, as we say, from Nature, we obtain both the materials of wealth and the force which helps us to turn the materials into wealth. Whatever thus furnishes us with the first requisite of production is called a #natural agent#, that is, something which acts for us and assists us (Latin, _agens_, acting). Among natural agents #land# is by far the most important, because, when supplied with abundant sunlight and, moisture, it may be cultivated and made to yield all kinds of crops. Accordingly, economists often speak of land, when their remarks would really apply as well to rocks and rivers. Three-quarters of the whole surface of the globe is covered with seas; but this vast extent of salt water furnishes little wealth, except whales, seals, sea-weed, and a few other kinds of animals and plants. Hence, when we speak of land, we really mean any source of materials--any natural agent, and we may say that #land = source of materials = natural agent#.