either metal, the metal that rises in value is at a premium, and, like every other commodity, measures its price in the over-estimated metal which alone serves in reality as the standard of value. The result of all experience and history with regard to this question is simply that, where two commodities perform by law the functions of a measure of value, in practice one alone maintains that
B. THEORIES OF THE UNIT OF MEASURE OF MONEY.
The circumstance that commodities are converted into gold only in ideas as prices and that gold is therefore turned into money only in idea, gave rise to the theory of the ideal unit of measure of money. Since, in the determination of prices, gold and silver serve only ideally as money of account, it was asserted that the names pound, shilling, pence, thaler, franc, etc., instead of denoting certain weights of gold and silver or labor incorporated in some way, stood rather for ideal atoms of value. Thus, if, e. g., the value of an ounce of silver should rise it would contain more such atoms and would therefore have to be estimated and coined in a greater number of