insures facility of transport, of transition from hand to hand and from one country to another, the ability to appear as rapidly as to disappear, in short, that material mobility which constitutes the sine qua non of the commodity that is to serve as the perpetuum mobile of the process of
The high specific value of the precious metals, their durability, comparative indestructibility, insusceptibility of oxidation through the action of the air, in the case of gold insolubility in acids except in aqua regia,—all these natural properties make the precious metals the natural material for hoarding. Peter Martyr who seems to have been a great lover of chocolate, remarks, therefore, of the cacao-bags which formed a species of Mexican gold: “O felicem monetam, quae suavem utilemque praebet humano generi potum, et a tartarea peste avaritiae suos immunes servat possessores, quod suffodi aut diu servari nequeat.”113
The great importance of metals in general in the direct process of production is due to the part they play as instruments of production. Apart from their scarcity, the great softness of gold and silver as compared with iron and even copper (in the