capable of being
acquired through usucapion by a purchaser in good faith, or by one who
possesses on some other lawful ground, unless they are free from all
flaws which vitiate the usucapion.

11 If there be a mistake as to the ground on which possession is
acquired, and which it is wrongly supposed will support usucapion,
usucapion cannot take place. Thus a man's possession may be founded on
a supposed sale or gift, whereas in point of fact there has been no sale
or gift at all.

12 Long possession which has begun to run in favour of a deceased person
continues to run on in favour of his heir or praetorian successor, even
though he knows that the land belongs to another person. But if the
deceased's possession had not a lawful inception, it is not available
to the heir or praetorian successor, although ignorant of this. Our
constitution has enacted that in usucapion too a similar rule shall
be observed, and that the benefit of the possession shall continue in
favour of the successor.

13 The Emperors Severus and Antoninus have decided by a rescript that a
purchaser too may reckon as his own the time during which his vendor has
possessed the thing.

14 Finally, it is provided by an edict of the Emperor Marcus that after
an interval of five years a purchaser from the treasury of property
belonging to a third person may repel the owner, if sued by him, by
an exception. But a constitution issued by Zeno of sacred memory has
protected persons who acquire things from the treasury by purchase,
gift, or other title, affording them complete security from the moment
of transfer, and guaranteeing their success in any action relating
thereto, whether they be plaintiffs or defendants; while it allows those
who claim any action in respect of such property as owners or pledges
to sue the imperial treasury at any time within four years from the
transaction. A divine constitution which we ourselves have lately issued
has extended the operation of Zeno's enactment, respecting conveyances
by the treasury, to persons who have acquired anything from our palace
or that of the Empress.

TITLE VII. OF GIFTS

Another mode in which property is acquired is gift. Gifts are of two
kinds; those made in contemplation of death, and those not so made.

1 Gifts of the first kind are those made in view of approaching death,
the intention of the giver being that in the event of his decease the
thing given should belong to the donee, but th