XV. Of ordinary substitution
XVI. Of pupillary substitution
XVII. Of the modes in which wills become
void
XVIII. Of an unduteous will
XIX. Of the kinds of and differences
between heirs
XX. Of legacies
XXI. Of the ademption and transference
of legacies
XXII. Of the lex Falcidia
XXIII. Of trust inheritances
XXIV. Of trust bequests of single things
XXV. Of codicils

TITLE I
OF THE DIFFERENT KINDS OF THINGS

In the preceding book we have expounded the law of Persons:
now let us proceed to the law of Things. Of these, some admit
of private ownership, while others, it is held, cannot belong to
individuals: for some things are by natural law common to all,
some are public, some belong to a society or corporation, and
some belong to no one. But most things belong to individuals,
being acquired by various titles, as will appear from what
follows.

1 Thus, the following things are by natural law common to all --
the air, running water, the sea, and consequently the sea-shore.
No one therefore is forbidden access to the sea-shore, pro-