Julianus, Digest, Book XXXIX. Where one of several heirs purchases a tract of land which has been left in trust, the price having been determined by the income from said land on account of the debts due from the estate; the party entitled to the land under the terms of the trust, being present, and consenting, it is settled that not the land itself, but the value of the same should be delivered. Marcellus states in a note, “If the heir should prefer to deliver the land, I think that he should be heard.” 1Julianus: Where money is bequeathed to Titius, and he is charged by a trust to manumit a slave belonging to another, and the master of said slave is unwilling to sell him; he will, nevertheless, be entitled to his legacy, because it was not his fault that the property bequeathed by the trust was not delivered. For if the slave should die, he will not be deprived of his legacy. 2Just as it is conceded that a trust can be imposed upon anyone who is entitled to an estate as the lawful heir, or to prætorian possession of it, so he who, by law, has a right to the estate of a boy under the age of puberty, or to prætorian possession of the same, can be legally charged with a trust.

Julianus, Digest, Book IX. A certain person made the following provision in his will: “My heir, I ask and charge you to transfer to my son whatever comes into your hands out of my estate, upon the first day; or if anything should happen to him before that time, I request you to deliver it to his mother.” The question arises if the boy should die before the estate is entered upon, whether his mother would be entitled to the benefit of the trust. I answered that if the boy should die before the time arrived for the execution of the trust, it would be transferred to his mother; but if he should die after the day for its execution arrived, the heir of the boy would be entitled to the benefit of the trust. But, in order to ascertain the intention of the testator, namely, whether if the boy should die before the delivery of the property under the trust, it would be transferred to the mother rather than to the heirs, the Prætor must take into consideration the person of the mother as well as that of the heir of the boy. Marcellus: It is, however, more in conformity with the will of the testator to hold that whenever the boy dies, whether he dies before the day for the execution of the trust, or afterwards, the trust will be transferred to his mother, if he should not already have received it. This is the rule which we now make use of. 1Where a slave is appointed heir, and his master is charged to deliver the estate to the slave when he shall become free, the trust is valid. 2When anyone appoints his son heir to his entire estate, and, by a codicil which he directed to be opened after the death of his son, he charges him to transfer his estate to his sister if he should die without issue, and the son, being aware of the contents of the codicil, directed by his will that the slave Stichus, who belonged to the estate of his father, should be free, the heirs of the son must pay the value of the slave to the sister of the deceased, for his freedom cannot be lost by means of a favor. Moreover, even if the son should not be aware that his father had made a codicil, his heirs will, nevertheless, be obliged to pay the value of the slave, in order that the act of one may not injure another. 3Ad Dig. 36,1,26,3Windscheid: Lehrbuch des Pandektenrechts, 7. Aufl. 1891, Bd. III, § 647, Note 11.If, however, this slave was appointed an heir by Sempronius, and after he had obtained his freedom, entered upon the same estate by the will of the brother, the heirs of the latter must also pay his sister the appraised value of the estate; because if the slave had not been manumitted, he could enter upon the estate by order of the woman. But if Sempronius should die during the lifetime of the son, deduction of the estate on account of the trust shall be made, since the slave, having been ordered to accept the estate by the son himself, will acquire it.