Celsus, Digest, Book I. A grandfather promised a dowry on behalf of his granddaughter by his son, and agreed that an action should not be brought for the dowry, either against himself or his son. Then, if an action for the dowry is brought against a party who is the co-heir of the son, the former cannot protect him by pleading an exception on the ground of contract; the son, however, can very properly make use of it, since a party is permitted to consult the best interest of his heir, and there is nothing in the way of his providing for one of his heirs, if he should become an heir, and not consult the interest of the others.

Celsus, Digest, Book I. Where an agreement is made in which there is no mention of an heir, the question arises whether this has been done in order that only the person of the party himself may be considered. But although it may be true that he who makes use of an exception must establish good ground for doing so; still, the plaintiff, and not he who pleaded the exception, must prove that the agreement merely had reference to himself, and did not include his heir, because in such cases, we generally provide for our heirs as well as for ourselves.

Celsus, Digest, Book I. The question as to whether the husband, in the discharge of his duties while transacting the business of his wife, has incurred expenses with reference to her property, is one of fact, and not of law. A conjecture based on the amount and character of the expenses incurred by him will not be difficult.

Celsus, Digest, Book I. No one has a right to renew an old debt by novation, solely because payment can sometimes legally be made to him. For payment can sometimes properly be made to those who are under our control, when none of them can, by himself, in accordance with law, substitute a new obligation for the old one.