; for a time limitation in a will is considered a
superfluity, and an heir instituted subject to such a time limitation is
treated as heir absolutely.

10 If the institution of an heir, a legacy, a fiduciary bequest, or a
testamentary manumission is made to depend on an impossible condition,
the condition is deemed unwritten, and the disposition absolute.

11 If an institution is made to depend on two or more conditions,
conjunctively expressed,--as, for instance, 'if this and that shall be
done'--all the conditions must be satisfied: if they are expressed
in the alternative, or disjunctively--as 'if this or that shall be
done'--it is enough if one of them alone is satisfied.

12 A testator may institute as his heir a person whom he has never seen,
for instance, nephews who have been born abroad and are unknown to him:
for want of this knowledge does not invalidate the institution.

TITLE XV. OF ORDINARY SUBSTITUTION

A testator may institute his heirs, if he pleases, in two or more
degrees, as, for instance, in the following form: 'If A shall not be
my heir, then let B be my heir'; and in this way he can make as many
substitutions as he likes, naming in the last place one of his own
slaves as necessary heir, in default of all others taking.

1 Several may be substituted in place of one, or one in place of
several, or to each heir may be substituted a new and distinct person,
or, finally, the instituted heirs may be substituted reciprocally in
place of one another.

2 If heirs who are instituted in equal shares are reciprocally
substituted to one another, and the shares which they are to have in
the substitution are not specified, it is presumed (as was settled by
a rescript of the Emperor Pius) that the testator intended them to take
the same shares in the substitution as they took directly under the
will.

3 If a third person is substituted to one heir who himself is
substituted to his coheir, the Emperors Severus and Antoninus decided
by rescript that this third person is entitled to the shares of both
without distinction.

4 If a testator institutes another man's slave, supposing him to be an
independent person, and substitutes Maevius in his place to meet the
case of his not taking the inheritance, then, if the slave accepts
by the order of his master, Maevius is entitled to a half. For, when
applied to a person whom the testator knows to be in the power of
another, the words 'if he shall not be my