Ad Dig. 7,1,62Windscheid: Lehrbuch des Pandektenrechts, 7. Aufl. 1891, Bd. I, § 184, Note 5.Tryphoninus, Disputations, Book VII. It is very properly held that an usufructuary has a right to hunt in the woods or on the mountains of the property in which he has the usufruct; and where he killed a wild-boar or a stag, he does not take anything belonging to the owner of the land, but he renders what he acquired his either by the Civil Law or in the Law of Nations. 1Where wild animals were kept in enclosures, when an usufruct becomes operative the usufructuary can make use of them, but he cannot kill them; but if, in the beginning, he encloses them by his own effort, and they are caught in traps by him, are they lawfully the property of the usufructuary? It is most convenient, however, on account of the difficult distinction that would arise as to the uncertain rights of the usufructuary with reference to different animals, to hold that it would be sufficient, at the termination of the usufruct, to deliver to the owner of the property the same number of different kinds of animals which existed at the time the usufruct became operative.

Ad Dig. 12,6,64Windscheid: Lehrbuch des Pandektenrechts, 7. Aufl. 1891, Bd. II, § 289, Note 26.Tryphoninus, Disputations, Book VII. Where a master owed money to his slave and paid him after he was manumitted, he cannot bring an action for its recovery; even though he paid thinking he was liable to proceedings to force him to do so, since he acknowledged a natural debt. For, as freedom exists under natural law and the domination of persons was introduced by the Law of Nations, the question as to whether a debt exists or not together with the right of action for its recovery, must be considered with reference to natural law.

Tryphoninus, Disputations, Book VII. A husband, after a divorce, through mistake paid a dowry which he had not received. He can recover it, because he can prove that it had not been paid to him, for it can not be exacted from him.

Tryphoninus, Disputations, Book VII. If anyone who is under the control of another finds a treasure, it must be said with reference to the person for whom it is acquired that if the former finds it upon the land of another, he will be entitled to half of it; but if he finds it upon the land of his father or master, the whole of it will belong to the latter; (and only half, if it is discovered upon the land of someone else). 1If a slave owned in common finds a treasure upon the land of another, will he acquire the same in proportion to the shares of his masters, or will he always acquire it for both of them equally? This case resembles one where property which is derived from the State, or bequeathed by a legacy, or donated by strangers, is delivered to a slave, because a treasure is considered a gift of fortune; hence the part to which the finder is entitled will belong to the joint-owners in proportion to the interest which each one has in the slave. 2If a slave owned in common finds a treasure on the land of one of his masters, no doubt can arise with reference to the share to which the master is always entitled, as it belongs to the owner of the land alone. But, on the other hand, it should be considered whether the other joint-owner will not have a right to part of the remaining half, and whether the case is not similar to that where a slave makes a stipulation by the order of one of his masters, or receives something by delivery, or specifically, for the other. The latter may be said to be the better opinion. 3Where a slave in whom anyone has the usufruct finds a treasure on the land of him who has the ownership of the slave, will it all belong to him? And if he finds it on the land of another, will he acquire half of it for his owner, or for the usufructuary? In this instance, an examination must be made to ascertain whether the usufructuary can acquire property by the labor of the slave. Suppose that the slave found a treasure by digging in the ground; then it may be said to belong to the usufructuary. If, however, he should suddenly find it concealed in some retired place, while he was doing nothing but walking about, it will belong to the owner of the property. I, however, do not think that half the treasure should belong to the usufructuary, for no one seeks for treasure with the labor of a slave, and it was not on his account that the slave was digging in the earth, but he was doing work for another purpose, and fortune gave him something else. Therefore, if he should find a treasure on the land of the usufructuary himself, I think that the latter will be entitled to only half of it, as the owner of the land, and that the other half will belong to him who has the ownership of the slave. 4If a creditor finds a treasure on land which has been hypothecated to him, he will be considered to have found it on the land of another. Hence, he can take half of it himself, and give the other half to the debtor; and when the borrowed money is paid, he can retain the half which he has taken from the treasure by the right of the finder, and not by the right of the creditor. This being the case, if the creditor has begun to hold the land as his own by the right of ownership, under the authority of the Emperor the claim to the pledge will be considered to exist during the time appointed for payment; but, after this time has elapsed, the debtor will be entitled to any treasure found on the land before the money has been paid. Where, however, the amount of the debt is tendered within the time prescribed by law, the creditor must return the treasure, as everything must be restored which belongs to the land, just as in the case where it is returned by a possessor; but he will only be obliged to surrender half of it, because it is settled that the finder is always entitled to half.

Tryphoninus, Disputations, Book VII. If Titius, desiring to make a donation to me, and having been delegated by me, promises my creditor, who is the stipulator, he will not be entitled to use the exception against him in such a way as to have judgment rendered against him to the extent of his means; but he can properly make such a defence against me, because I demanded what he had already given him. The creditor, however, can collect the debt.