Julianus, Digest, Book LXI. It makes no difference whether a legacy becomes void in the beginning, or something occurs subsequently on account of which an action cannot be brought by the legatee to recover it.

The Same, Digest, Book LXI. Where a man left an estate composed of a tract of land worth a hundred aurei, and charged his heir to sell it to Titius for fifty, he should not be considered to have devised more than fifty, and therefore the Falcidian Law will not apply. 1Moreover, where a testator has an estate composed of two tracts of land, each worth a hundred aurei, and appoints Titius and myself his heirs, and charges me to sell the Cornelian Estate to Titius for fifty aurei, and, on the other hand, charges Titius to sell the Seian Estate to me for fifty aurei, I do not think that the Falcidian Law will apply, as each of the heirs will be entitled to half of one of the tracts of land by hereditary right, which is equal to half of the estate. For there is no doubt that the one who is charged to sell the Cornelian Estate will be entitled by hereditary right to half of the Seian Estate, and also he who is charged to sell the Seian Estate can retain by hereditary right the half of the Cornelian Estate. 2If any one should appoint as his heir a person to whom he had been asked to pay a hundred aurei at his death, the hundred aurei should be deducted in computing the proportion due under the Falcidian Law, because if anyone else had been the heir, the said hundred aurei would have been included among the debts of the estate. 3If you and Titius are each appointed heirs to the fourth part of an estate, and then you are appointed heirs to the remaining half under a condition, and legacies, as well as the freedom of slaves, have been bequeathed, they should obtain their freedom, and all the legacies should be paid while the condition is pending; because, if the condition is complied with, and you should become the heir, both the legacies and the grants of freedom will be valid; or if the condition should fail, Titius and yourself will become the heirs. If you ask how the Falcidian portion can be estimated, and whether, when the condition is fulfilled, your quarter and your half of the estate should be combined, and hence the Falcidian portion must be calculated on three-fourths of the estate, if you pay the legacies with which you are absolutely charged as heir, we give it as our opinion that the two shares should be combined. 4Ad Dig. 35,2,87,4Windscheid: Lehrbuch des Pandektenrechts, 7. Aufl. 1891, Bd. III, § 652, Note 8; Bd. III, § 653, Note 11.Where a testator appointed his son, who was under the age of puberty, and Titius, heirs to equal shares of his estate, and charged his son with legacies amounting to his entire half, but charged Titius with nothing, and substituted Titius for his son, Titius having entered upon the estate under his appointment, and the minor son having died, and Titius having become his heir by virtue of the substitution, the question arose how much he should pay as legacies. It was decided that he must pay the legacies in full, for the two halves of the estate having become merged, cause the Falcidian Law to apply to the entire inheritance, and hence the legacies would be due without any deduction. This is, however, true only where the son dies before becoming the heir of his father. But if he should become his heir, the substitute ought not to pay more of the legacies than the minor would have been compelled to do, because he is not bound in his own name, but in that of the deceased minor, who would not have been required to deliver more than three-fourths of his half to the legatees. 5Ad Dig. 35,2,87,5Windscheid: Lehrbuch des Pandektenrechts, 7. Aufl. 1891, Bd. III, § 653, Note 11.If, however, the entire half of the foreign heir should have been bequeathed, and he, by virtue of pupillary substitution, becomes heir to the minor, who was not charged with the payment of any legacies, it can be said that they will be increased, and proceedings must be taken just as if the party had been substituted for any heir whomsoever, and the latter having refused to accept the estate, the substitute becomes entitled to all of it; for the reason that the substitute, in fixing the portion due under the Falcidian Law, always takes into consideration the amount of the property which the father left. 6The same must be said if the father should appoint his two minor children his heirs, and substitute them for one another, as under these circumstances the estate will vest in the other by the right of substitution, and the amount of the Falcidian Law must be established. 7Where a testator had two minor sons, and appointed one of them his heir, and disinherited the other, and subsequently substituted the disinherited son for the one whom he had appointed heir, and then substituted Mævius for the one whom he had disinherited, and charged him with the payment of legacies, the disinherited brother became the heir to the other, and afterwards died. As, by his father’s will, the estate of the latter passed to him by hereditary right under the terms of the substitution, it can be said that the legacies with which he was charged must, after deducting the Falcidian portion, be paid out of the property which the father left at the time of his death. The following case is not opposed to this opinion, namely: when a father bequeaths a legacy to his disinherited son, the substitute is not obliged to pay the legacy on this account; because, in this instance, the son does not receive a part of his father’s estate but only a legacy. Still, someone may ask what must be done if the disinherited son did not become the heir of his brother under the substitution, either by law, or through the intervention of some third party, and then should die before reaching the age of puberty. Could it be held, under such circumstances, that the substitute must pay the legacy with which he was charged? By no means. For it makes a difference whether the disinherited son becomes the heir of his brother by virtue of the substitution or in some other way, and it is clear that in one of these cases the father can charge the son with a legacy, but in the other he cannot; and hence it is agreeable to reason to hold that the testator has no more right with reference to the substitute than he would have had with reference to him for whom he was appointed. 8Ad Dig. 35,2,87,8Windscheid: Lehrbuch des Pandektenrechts, 7. Aufl. 1891, Bd. III, § 653, Note 11.The co-heir of a minor, after reserving the Falcidian portion, paid the legacies bequeathed by the testator in proportion to his share of the estate. Then the minor having died, the other became his heir by virtue of the substitution, and the half of the estate which belonged to the minor having been exhausted, the portion due under the Falcidian Law should be deducted from all the legacies, so that all of them with which he and the minor were charged having been subjected to contribution, the fourth part of the estate will remain in his possession; for although he is the heir of the minor, still the deduction under the Falcidian Law must be made, just as if he had been the heir of his father. The legacies with which the heir was charged, and which amounted to more than three-fourths of his share, will not be increased unless the heir who was appointed to a part of the estate and substituted for his co-heir, should pay the legacies, after having deducted the Falcidian portion, while his co-heir was deliberating; and then, after the latter had rejected the estate, the other, by virtue of the substitution, should also acquire the remaining part of the same.