Again, if it be true, as Jevons says, that gold is one of the last things to be regarded as wealth, and the labour expended in its production almost a dead loss, and therefore a wrong to the human race, the world should be very much poorer for all the enormous production of the last half-century. On the contrary, the world has gone on increasing in the appliances of wealth, in conditions of comfort, and in diffusion of education. The addition to the world’s stock of gold has permitted the creation of an enormous amount of gold-certificates, as bank-notes and bills of exchange may be regarded, the existence of which has facilitated commercial operations which otherwise would not have been possible. In theory, we exchange our coal and iron for the cotton, wheat, &c., of other countries; but as we cannot mete out the exactly equal values in ‘kind,’ we settle the difference nominally in gold, but actually in paper representing gold. But the gold must nevertheless exist, or the operation would be impossible. It is as when a man buys, let us say, five hundred tons of pig-iron in Glasgow. He does not actually receive into his hands five hundred tons of iron, but he receives a warrant which entitles him to obtain such iron when and how he pleases. Though the purchaser may never see the iron which he has bought, the iron must be there, and producible at his demand. On the faith of the transaction, he knows that he has command over five hundred tons of iron; none of which may perhaps, save the ‘sample,’ have come under his cognisance. Of course there is no complete analogy between an iron warrant and a paper currency, but it serves for the moment as a simple illustration. To discuss the differences would lead us beyond the design of the present paper. Probably one great reason why gold so early in the history of the world assumed its leading position as a standard of value is, that it is found in a pure state. So also is silver, which is the nearest rival of gold. Primitive races used these metals long before the art of smelting was discovered. These two metals were both rare, both found pure, both easily refined, both admitting of a splendid polish, both malleable and ductile, both durable. Silver is more destructible than gold, less durable, less rare, and even less useful in some respects. It has, therefore, always had a lower value than gold.