A seignorage will, in many cases, take away altogether, and will, in all cases, diminish the profit of melting down the new coin. This profit always arises from the difference between the quantity of bullion which the common currency ought to contain, and that which it actually does contain. If this difference is less than the seignorage, there will be loss instead of profit. If it is equal to the seignorage, there will neither be profit nor loss. If it is greater than the seignorage, there will indeed be some profit, but less than if there was no seignorage. If, before the late reformation of the gold coin, for example, there had been a seignorage of five percent upon the coinage, there would have been a loss of three percent upon the melting down of the gold coin. If the seignorage had been two percent there would have been neither profit nor loss. If the seignorage had been one percent there would have been a profit, but of one percent only instead of two percent. Wherever money is received by tale, therefore, and not by weight, a seignorage is the most effectual preventative of the melting down of the coin, and, for the same reason, of its exportation. It is the best and heaviest pieces that are commonly either melted down or exported; because it is upon such that the largest profits are made.
The law for the encouragement of the coinage, by rendering it duty-free, was first enacted, during the reign of Charles II for a limited time; and afterwards continued, by different prolongations, till 1769, when it was rendered perpetual. The bank of England, in order to replenish their coffers with money, are frequently obliged to carry bullion to the mint; and it was more for their interest, they probably imagined, that the coinage should be at the expense of the government, than at their own. It was, probably, out of complaisance to this great company that the government agreed to render this law perpetual. Should the custom of weighing gold, however, come to be disused, as it is very likely to be on account of its inconveniency; should the gold coin of England come to be received by tale, as it was before the late re-coinage, this great company may, perhaps, find that they have upon this, as upon some other occasions, mistaken their own interest not a little.