73. Laws of Supply and Demand. In the next place, we must try to understand how the values of things are governed, and made to change from time to time. The principal laws which govern values are called the laws of supply and demand, and they are very important indeed. Supply means the quantity of any goods which people are willing to give in exchange at a certain value, and demand means similarly the quantity of goods which people are willing to take in exchange; but, before a person can judge how much he wishes to buy of a particular kind of goods, he must know its price, that is, its proportion in exchange for money. If bread, instead of being threepence per pound, becomes fourpence, a poor person would perhaps decide to take less bread, and to buy more potatoes. If beef, instead of being ninepence, should rise to a shilling, or fourteenpence a pound, some people would refuse to buy it altogether, and others would buy less than before. The supply of things varies similarly; if the price of meat rises high, farmers who own cattle bring them to market, in order to get a good profit by selling them; if the price falls low, they keep their cattle to sell at another time.

The Laws of Supply and Demand may be thus stated: a rise of price tends to produce a greater supply and a less demand; a fall of price tends to produce a less supply and a greater demand. Conversely, an increase of supply or a decrease of demand tends to lower price, and a decrease of supply or an increase of demand to raise price.

These laws are so important that I will state them over again, in the form of a table :

We can now understand how the price of any kind of goods is decided. The price must be such that the quantity demanded at any time is equal to the quantity supplied. If those who want goods at a certain price, cannot get them, they will have to offer a higher price, so that they may induce other people to sell. The higher the price the greater the supply, as we have seen; moreover, if some people in a market are offering a higher price, it soon becomes known to other dealers. When a farmer's wife carries a basket of butter to sell at the Butter Cross in the neighbouring market town, she soon learns whether the supply is greater or less than usual. If the purchasers are few and slow in buying, she begins to fear that she may have to carry her butter back unsold, and go without the crockery and calico and other things which she intended to buy with the money. Then she begins to ask a penny or twopence a pound less, and the other sellers of butter are obliged to lower their prices also, since no one would buy butter from one woman at 1s. 6d., if he could get it as good from the next person at 1s. 4d. But, if few people bring butter to market, or if there are many purchasers with money in their pockets, the scene is quite changed. Those who have brought butter, find that they will have no difficulty in selling all they have; it is the purchasers who now become anxious to buy before all is gone, and their eagerness soon shows the sellers that they may ask higher prices. It is by this higgling of the market, by sellers asking the highest price they think they can get, and buyers trying to buy at the lowest price which they think will be taken-that the market price of any commodity is settled.

The market price will be such that the demand at that price will equal the supply at that price. The quantity of butter or any other commodity that is sold must equal what is bought, because it is not sold until it is bought; but the price will settle itself accordingly.

74. How Value depends upon Labour. We now come to the great question whether value is produced by labour, or how it is connected with labour. Some economists, observing that, when a thing like gold is very valuable, men spend a great deal of labour in getting it, have said that the labour spent upon it is the cause of the high value. This is quite wrong; for if it were true, anything, upon which great labour has been spent, ought to be very valuable; everybody knows that such is not the case. Great labour may be expended in writing, printing, and binding a book; but, if nobody wants the book, it is valueless, except as waste paper. A vast amount of labour was spent on building the Thames Tunnel, but, as few people wished to go through it, the tunnel was of small value, until it was required for a railway. Thus it is quite certain that we cannot make a thing valuable by simply labouring at it; we must labour in such a way as to make the thing useful.

On the other hand, substances may be very valuable which have cost little or no labour. When a shepherd in Australia happens to pick up a nugget of gold on the mountain side, it takes no labour worth mentioning to pick it up, yet the gold is just as valuable in proportion to its weight as any other gold. Some gold mines produce a great quantity of gold: others which have cost quite as much to sink, produce little; nevertheless the gold out of the one mine is sold at the same price in proportion to its weight and fineness as that out of the other mine. Thus it is quite certain that labour is not the cause of value. Gold is valuable because a great many people want more gold than they have already got, and wh a thing is valuable it is because somebody w But we may look at this matter in anoth it were possible to get a valuable thing little labour, many people would becom Much gold would then be produ

wanted as much as what was already in use, it would be as valuable. But no one wants an unlimited quantity of any substance. Wealth, as we saw, must be limited in supply; if gold became as plentiful as lead or iron, it could not possibly remain as valuable as it is now. People would have far more than they could employ for ornaments, watches, gilding and so forth; there would be a large surplus to be used in making pots and pans, for which it is less needed. Now we can see through the whole subject of value. When, much of a substance can usually be produced with little labour, the substance becomes so plentiful that people are satisfied with the supplies of it which they have; they do not want more, or at least do not want it so urgently. It follows that they are unwilling to give much wealth for it. Thus the labour spent upon producing a commodity does not affect the value of that commodity, unless it alters the quantity of it which people can get, and thus makes a further supply of the commodity more or less useful than before.

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.

CHAPTER XII.

MONEY.

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.

If, for instance, I want a telescope, in exchange for