Base metals not fit materials of money.

24. Again, it is requisite that that metal which is made money, or the standard measure of commerce, should be either of equal goodness every where, according to its quantity or weight; or, that there should be some certain criterion, by which might be ascertained, the true proportional value of any given mass of that metal, when compared with any other given mass of the same metal. Money cannot be a proper or exact measure of the values of other things, if its own value is questionable; for if it could be doubted, whether my ounce of money, be precisely of the same value with any other person’s ounce of money; it would create such a distraction in all kinds of traffic, that would frustrate the very end and design of money.

The base metals, as copper, tin, lead, and iron; have none of them the above quality, or that precise certainty of value, required in money. For, although the artists employed about them, can soon find that this mass of copper, for instance, is better or worse than that other mass, at least for their particular purposes; yet, there is no method of ascertaining, to any exactness, what is their respective pureness; or what is the specific difference betwixt, or what is the true proportional value of, different masses of that metal in respect of one another. And therefore copper, is not a fit material for money: And the other base metals, are still more unfit; for the like, and other reasons, that are sufficiently obvious. Their great plenty and cheapness, is a farther objection to the making money of any of the baser metals.