Now of all objects Gold and Silver best fulfil all these requirements. Precious stones are more portable, value for value. A £1,000 worth of diamonds takes up less space and is less heavy than a £1,000 worth of gold. And precious stones are fairly stable in value and also keep very well; but they are not easily divisible. Again, they are not of the same standard value in all cases. They vary in purity. But gold and silver have all the qualities required. Gold hardly decays at all through the passage of time, and silver very little; and each, but especially gold, is valuable for its bulk, and its value is fairly stable, and each is easily divisible and can therefore be presented in any amount, from a tenth of an ounce to a hundred pounds weight. So, by the mere force of things, Gold and Silver became the Money of mankind. People kept gold and silver by them in order to effect their exchanges, and very soon a producer did not feel himself to be exchanging at all (in the sense of exchanging goods against goods), but thought of the affair as _Buying and Selling_. That is, of exchanging his produce, not against other produce, but against gold and silver, with the object of _later_ re-exchanging that gold and silver for other things that he needed. Money, once thus established, is called =A MEDIUM OF EXCHANGE= and also =CURRENCY= or =THE CIRCULATING MEDIUM=. It is called “currency” and “circulating” because it goes its round through society, effecting the exchanges, and this running around or circulating gives it its name: “That which is current” from the Latin for “running.” That which “circulates” from the late Latin word for “going the rounds.” When gold and silver become the money of mankind it is important to be able to tell at once the exact amounts you are dealing with. This, under simple conditions, is done by weighing; but it is more convenient to stamp on separate bits of metal what weight there is in each, and that is called “coining the metal.” All that a Government does when it makes a sovereign is to guarantee that there is so much weight of gold in the round disc of metal which it stamps. Money does not only fill this main function of being a medium of exchange, that is, of making a vast quantity of complicated exchanges possible, it also has great social value as a measurer or standard, and soon after money comes into use men begin to think of the economic values of things in terms of money: that is, in what we call “=Prices=.”