The Same, Stipulations, Book III. If a promisor should become the heir of the person jointly liable with him, it must be said that he is bound by two obligations; for where there is some difference between the obligations, as in the case of a surety and the principal debtor, it is established that one obligation is annulled by the other. When, however, the obligations are of the same nature, it cannot be determined why one of them should be disposed of rather than the other. Hence, if one joint-stipulator should become the heir of the other, he will be entitled to two distinct obligations.

Venuleius, Stipulations, Book III. If I stipulate for something to be given me, and I afterwards stipulate for the same thing with the same person under a condition, with the intention of making a novation, the property must remain in existence in order for there to be ground for the novation, unless the promisor was required to give it. Therefore, if you are obliged to deliver me a slave, and you are in default in doing so, you will be liable even if the slave should die, and if, before he dies, you are already in default, and I stipulate with you for the same slave under a condition, and the slave afterwards dies, and then the condition is fulfilled, as you are already liable to me under the stipulation, novation will alscr take place. 1Ad Dig. 46,2,31,1ROHGE, Bd. 4 (1872), S. 217: Liberation eines Schuldners ohne dessen Wissen durch Zahlung bez. Angabe an Zahlungsstatt, Novation eines Dritten.ROHGE, Bd. 16 (1875), Nr. 82, S. 328: Ersatzanspruch aus der Tilgung bezw. Uebernahme der Schuld eines Andern.Windscheid: Lehrbuch des Pandektenrechts, 7. Aufl. 1891, Bd. II, § 295, Note 5; Bd. II, § 354, Note 15.Where there are two joint-stipulators, the question arises whether one of them has the right to make a novation, and what right each acquires for himself. Generally speaking, it is established that payment may properly be made to one, and that if one institutes proceedings he brings the entire matter into court, just as where one is released, the obligation of both is extinguished. From this it may be gathered that each of them acquires for himself, just as if he alone had stipulated; except that each of them, by the act of him with whom the stipulation was jointly made, can lose his debtor. According to this, if one of the joint-stipulators enters into another agreement with a third party, he can, by novation, release him from liability to the other joint-stipulator, if such was his express intention; and there is all the more reason for this, as we think that the stipulation resembles payment. Otherwise, what shall we say if one of them delegates the common debtor to his creditor, and the latter stipulates with him; or a woman orders a tract of land to be promised to her husband by way of dowry; or, if she was about to marry him, she should promise him the land as dowry? The debtor would be released, so far as both parties are concerned.