enemy at once become ours by the law of nations, so that by
this rule even free men become our slaves, though, if they
escape from our power and return to their own people, they
recover their previous condition. 18 Precious stones too, and
gems, and all other things found on the sea-shore, become
immediately by natural law the property of the finder: 19 and
by the same law the young of animals of which you are the
owner become your property also.

20 Moreover, soil which a river has added to your land by
alluvion becomes yours by the law of nations. Alluvion is an im-
perceptible addition; and that which is added so gradually that
you cannot perceive the exact increase from one moment of
time to another is added by alluvion. 21 If, however, the
violence of the stream sweeps away a parcel of your land and
carries it down to the land of your neighbour it clearly remains
yours; though of course if in the process of time it becomes
firmly attached to your neighbour's land, they are deemed
from that time to have become part and parcel thereof. 22
When an island rises in the sea, though this rarely happens,
it belongs to the first occupant; for, until occupied, it is held
to belong to no one. If, however (as often occurs), an island
rises in a river, and it lies in the middle of the stream, it belongs
in common to the landowners on either bank, in proportion
to the extent of their riparian interest; but if it lies nearer to
one bank than to the other, it belongs to the landowners on
that bank only. If a river divides into two channels, and by
uniting again these channels transform a man's land into an
island, the ownership of that land is in no way altered: 23
but if a river entirely leaves its old channel, and begins to