The former are purely mischievous, both to the country imposing them, and to those with whom it trades. They prevent a saving of labour and capital, which, if permitted to be made, would be divided in some proportion or other between the importing country and the countries which buy what that country does or might export. The other class of duties are those which do not encourage one mode of procuring an article at the expense of another, but allow interchange to take place just as if the duty did not exist--and to produce the saving of labour which constitutes the motive to international as to all other commerce. Of this kind, are duties on the importation of any commodity which could not by any possibility be produced at home; and duties not sufficiently high to counterbalance the difference of expense between the production of the article at home, and its importation. Of the money which is brought into the treasury of any country by taxes of this last description, a part only is paid by the people of that country; the remainder by the foreign consumers of their goods. Nevertheless, this latter kind of taxes are in principle as ineligible as the former, although not precisely on the same ground. A protecting duty can never be a cause of gain, but always and necessarily of loss, to the country imposing it, just so far as it is efficacious to its end. A non-protecting duty on the contrary would, in most cases, be a source of gain to the country imposing it, in so far as throwing part of the weight of its taxes upon other people is a gain; but it would be a means of gain which it could seldom be advisable to adopt, being so easily counteracted by a precisely similar proceeding on the other side. If England, in the case already supposed, sought to obtain for herself more than her natural share of the advantage of the trade with Germany, by imposing a duty upon cloth, Germany would only have to impose a duty upon linen, sufficient to diminish the demand for that article about as much as the demand for cloth had been diminished in England by the tax. Things would then be as before, and each country would pay its own tax. Unless, indeed, the sum of the two duties exceeded the entire advantage of the trade; for in that case the trade, and its advantage, would cease entirely.