Ulpianus, On Sabinus, Book XL. A pledge can be contracted not only by delivery, but also by mere agreement, even if no delivery is made. 1Let us therefore consider where a pledge has been contracted by mere agreement, whether, when anyone exhibits some gold as if he intended to deliver it by way of pledge, and he delivers brass, he will bind himself to pledge the gold? If follows that he will bind himself for the gold, but not for the brass, as the parties did not make an agreement with reference to the latter. 2However, where anyone when he delivers brass by way of pledge, states that it is gold, and gives it in pledge, it should be considered whether he does not make the brass a pledge, and whether as an agreement was made as to what was to be given, it may not be held to be pledged? This is the better opinion; still, the party who gave it will be liable to a counter action on pledge, without taking into account the fraud which he perpetrated.

Ulpianus, On Sabinus, Book XL. Where anyone allows himself to be directed by another to lend him money, he is understood to have received a mandate.

Ulpianus, On Sabinus, Book XL. A ward cannot legally bind himself to his guardian by the authority of the latter. It is clear that, when there are several guardians, it must be held that the authority of one of them is sufficient to enable the ward to bind himself to another, whether he lends him money, or enters into a stipulation with him. Where, however, there is only one guardian, and he lends money to his ward, or enters into a stipulation with him, he will not be bound to the guardian, but he will be naturally liaable to him for the amount by which he has been pecuniarily benefited. For the Divine Pius stated in a Rescript that an action should be granted in favor of the guardian against the ward, and indeed against anyone else, for the amount by which he was enriched at his expense through the transaction. 1A ward who makes a purchase or a sale without the authority of his guardian will only be liable for the amount by which he profits pecuniarily. 2Moreover, a guardian cannot contract the obligation of either buyer or seller with his ward. Where, however, he has a fellow-guardian, the authority of the latter will undoubtedly be sufficient to empower him to make a purchase. But if the transaction is fraudulent it will be of no effect, and hence the property cannot be acquired by usucaption. If, however, the ward, having attained his majority, confirms the purchase, the contract will be valid. 3If a guardian should buy property of his ward through the interposition of a third party, the purchase made under such circumstances will be void, because the transaction does not appear to have been concluded in good faith. This was also stated in a Rescript by the Divine Severus and Antoninus. 4If, however, he should make the purchase openly, and give another name, not fraudulently, but without concealment, as persons of rank are accustomed to do who do not wish their names to appear on the records, the purchase will be valid. But where he makes the purchase craftily, it will be the same as if he had made it by the agency of another person. 5If the creditor of the ward should sell his property, his guardian can purchase it in good faith. 6If the son of a guardian, or any other person under his control, should purchase the property, it will be the same as if he himself had purchased it.

Ulpianus, On Sabinus, Book XL. When we say that a guardian cannot grant authority to his ward to transact business with him; this is only true where the stipulation is acquired by him, or by persons under his control. But there is nothing to prevent his authority from being exercised in the transaction of any business by which his ward will be benefited. 1Where there are two creditors, and one of them stipulates for the payment of the debt by a ward, under the authority of one guardian, and the other stipulates for its payment by the ward with the authority of another guardian, it must be held that the stipulation is valid, provided the authority of one guardian is sufficient; but if it is not sufficient, it must be said that the stipulation is void. 2Where a father and his son, who is under his control, are both guardians, and the father stipulates with the authority of the son, the stipulation will be of no effect, and this is the case because the son cannot authorize any transaction in which his father is concerned.

Ulpianus, On Sabinus, Book XL. No one who is in possession of a slave either by force or clandestinely, or by a precarious title, can acquire a right to him by any stipulation he may enter into, or by delivery of the property.

Ulpianus, On Sabinus, Book XL. In an action for theft, it is sufficient for the property to be described in such a way that it can be understood what it is. 1It is not necessary to mention the weight of vessels, therefore it will be sufficient to say a dish, a plate, or a bowl. The material of which the article is composed must, however, be stated; that is, whether it is of silver, or gold, or anything else. 2Where anyone brings suit for unmanufactured silver, he should say an ingot of silver, and give its weight. 3The number of coins which have been stolen from the owner must be included, for instance, so many aurei, or more. 4The question arises whether the color of a garment should be mentioned. It is true that this should be done, for, just as where a theft of plate is involved, a golden bowl is mentioned, so, where a garment is concerned, the color should be stated. It is clear that if anyone should swear that he cannot positively designate the color, the necessity of the case should excuse him. 5Where anyone gives property in pledge, and then steals it, he will be liable in an action for theft. 6The owner is not only considered as guilty of the theft of property which has been pledged, when he takes it from the creditor who possesses or holds it, but also if he should remove it at a time when he did not possess it; for instance, if he should sell the article which had been pledged; for it is settled that, under such circumstances, he commits theft. Julianus, also, is of this opinion.