denomination of weight was retained for a constantly changing and decreasing weight of precious metals in their function of a standard of price. Thus the English pound sterling denotes less than one-third of its original weight; the pound Scot, before the Union, only 1-36; the French livre, 1-74; the Spanish Maravedi, less than 1-1000; the Portuguese Rei, a still smaller fraction. Such was the historical origin of the discrepancy between the current money names of various weights of metals and their weight denominations.42 Since the determination of the unit of measure, of its aliquot parts, and of their names is purely conventional, and since they should possess within the sphere of circulation the character of universality and compulsion, they had to be settled by law. The purely formal operation thus devolved upon the government.43 The metal which was to serve as the money material, was found already adopted in the community. In different countries the legal standard of price is naturally different. In England e. g. the ounce as a weight of metal is divided into pennyweights, grains and carats Troy, but the ounce of gold as the unit of money is divided into 3 7-8 sovereigns, the sovereign into 20 shillings, the shilling into 12 pence, so that 100 pounds of 22 carat gold (1200 ounces) = 4672 sovereigns and 10 shillings. In the world market, however, where national boundaries disappear, these national characteristics of the measure of money also disappear and give place to the general measures of weight of metals.
The price of a commodity or the quantity of gold into which it is ideally transformed, is, therefore, now expressed in the names of coins of the gold standard. Thus, instead of saying: a quarter of wheat is worth an ounce of gold, it is said in England to be worth 3£ 17s. 10-1/2d. All prices are thus expressed in the same denominations. The peculiar form which commodities lend to their exchange values is transformed into a money-denomination by which commodities tell each other how much they are worth. Money in its turn becomes money of account.44
We transform commodities into money of account, in our mind, on paper, in conversation, whenever it is a question of expressing any kind