Let it be further considered, that the duty called tonnage, in the
United States, is in lieu of the duties for anchorage, for the support
of buoys, beacons, and light-houses, to guide the mariner into harbor
and along the coast, which are provided and supported at the expense of
the United States, and for fees to measurers, weighers, guagers, &c,
who are paid by the United States; for which articles, among many others
(light excepted), duties are paid by us in the ports of France, under
their specific names. That government has hitherto thought these duties
consistent with the treaty; and consequently, the same duties under a
general instead of specific names, with us, must be equally consistent
with it: it is not the name, but the thing, which is essential. If we
have renounced the right to lay any port duties, they must be understood
to have equally renounced that of either laying new or continuing the
old. If we ought to refund the port duties received from their vessels
since the date of the act of Congress, they should refund the port
duties they have received from our vessels since the date of the treaty,
for nothing short of this is the reciprocity of the treaty.

If this construction be adopted, then each party has for ever renounced
the right of laying any duties on the vessels of the other coming
from any foreign port, or more than one hundred sols on those coming
coastwise. Could this relinquishment be confined to the two contracting
parties alone, its effect would be calculable. But the exemption
once conceded by the one nation to the other, becomes immediately
the property of all others who are on the footing of the most favored
nations. It is true, that those others would be obliged to yield the
same compensation, that is to say, to receive our vessels duty free.
Whether France and the United States would gain or lose in the exchange
of the measure with them, is not easy to say.