pable of acting
as a ship of war, by the arms of the other belligerent, and
driven into a neutral port for shelter; whether the purchase
of such a ship can be allowed, which shall enable the enemy
so far to rescue himself from the disadvantage into which he
has fallen, as to have the value restored to him by a
neutral purchaser, is a question on which I shall wait for
the authority of a superior court, before I admit the
validity of such a transfer."[163]

It has been said that the sale must be absolute and unconditional; so
that a sale under a condition to re-convey at the end of the war, is
invalid.[164] Similarly, where the seller is bound by his own
government under a penalty not to sell, except upon a condition of
restitution at the end of the war, and the purchaser undertook to
exonerate the seller, the sale was held invalid.[165]

SECTION II.

_Contraband of War_.

[Sidenote: Contraband of War.]

The general freedom of neutral commerce is subject to certain
restrictions with respect to neutral commerce. Among these is the
trade with the enemy in certain articles, called _Contraband of War_.
These are generally warlike stores, and articles which are directly
auxiliary to warlike purposes. Writers on this subject have made
distinctions between those things useful only for the purposes of war,
those which are not so, and those which are susceptible of
indiscriminate use in war and peace.

All seem to agree in excluding the first class from neutral trade;
and, in general, admitting the second. The chief difference is about
the third class. The last kind of articles--for example, money,
provisions, ships, and naval stores, according to Grotius, are
sometimes lawful articles of neutral trade, and sometimes not; and the
question depends upon circumstances. This is perhaps the truest ground
of decision, as we shall see in subsequent illustrations.[166]

Thus, these articles become contraband, _ipso facto_, if carried to a
besieged town, camp, or port. So in a _naval_ war, ships and materials
for ships, are contraband, although timber and cordage may be used for
other purposes, besides fitting out ships of war; and so horses and
saddles are not of necessity warlike stores, except when comparing the
quality, manufacture, or quantity attempted to be imported into the
hostile state, with the circumstances and condition of the war, it
appears (if not to be impossible