#75. Why Pearls are valuable#. To make this still more plain, let us endeavour to answer this difficult question, "Do men dive for pearls because pearls fetch a high price, or do pearls fetch a high price because men must dive in order to get them?" Pearl-diving is a very dangerous and laborious kind of work. The divers have to jump into the deep sea with heavy weights to carry them down, and they must hold their breath a long time while they are engaged in collecting the oyster shells at the bottom. The number of good pearls which they generally get is small compared with the great toil of getting them. It follows that, on the average, they must receive a high price for what they do find, otherwise they would not have adequate wages for such work. But this alone is not a sufficient reason for the pearls being so valuable, otherwise the mother of pearl shells, in which the pearls are found, and brought up, would be as valuable as the pearls. But mother of pearl is a very cheap substance. Again, if it were merely a question of labour, a diver might go down anywhere, and, bringing up the first stone or shell he found, insist on selling it for a high price, because he had dived for it. The truth is, that pearls are valuable because there are many ladies who have not got pearl necklaces, and who would like to have them; and those who have some pearls would like to get more and finer ones. In short, then, pearls are valuable because they are useful to ladies who want more pearl ornaments: they are thus useful because the ladies have not hitherto been able to get as many as they would like; and they have not been able to get many, because it is so difficult to fish them up from the bottom of the sea. Here we have the whole theory of value and labour. #The labour which is required to get more of a commodity governs the supply of it; the supply determines whether people do or do not want more of it eagerly; and this eagerness of want or demand governs value.#
#76. Barter.# When exchanges are made by giving one ordinary commodity for another, as a sack of corn for a side of bacon, or a book for a telescope, we are said to #barter# them. The operation is also called #truck# (French, _troc_, barter). Among uncivilised races trade is still carried on in this way; a traveller going into the interior of South Africa takes a stock of beads, knives, pieces of iron, looking-glasses, &c., in order that he may always have something which the natives will like to receive in exchange for food or services. People still occasionally barter things in England, or the United States, but this is seldom done, owing to the trouble which it gives.