vary, the quoted exchange will always differ 10, 15, or 20 per cent from it. However high this nominal premium may be, it has no tendency to send gold out of the country for the purpose of drawing a bill against it and profiting by the premium; because the gold so sent must be procured, not from the banks and at par, as in the case of a convertible currency, but in the market, at an advance of price equal [pg 438] to the premium. In such cases, instead of saying that the exchange is unfavorable, it would be a more correct representation to say that the par has altered, since there is now required a larger quantity of American currency to be equivalent to the same quantity of foreign. The exchanges, however, continue to be computed according to the metallic par. The quoted exchanges, therefore, when there is a depreciated currency, are compounded of two elements or factors: (1) the real exchange, which follows the variations of international payments, and (2) the nominal exchange, which varies with the depreciation of the currency, but which, while there is any depreciation at all, must always be unfavorable. Since the amount of depreciation is exactly measured by the degree in which the market price of bullion exceeds the mint valuation, we have a sure criterion to determine what portion of the quoted exchange, being referable to depreciation, may be struck off as nominal, the result so corrected expressing the real exchange.
The same disturbance of the exchanges and of international trade which is produced by an increased issue of convertible bank-notes is in like manner produced by those extensions of credit which, as was so fully shown in a preceding chapter, have the same effect on prices as an increase of the currency. Whenever circumstances have given such an impulse to the spirit of speculation as to occasion a great increase of purchases on credit, money prices rise, just as much as they would have