Javolenus, On Plautius, Book II. Where a party sold an estate and transferred it to the purchaser, but failed to retain what the deceased owed him, he can bring an action for its recovery; as anything which is paid in excess of what is due can properly be recovered by a personal action.

Javolenus, On Plautius, Book II. Where a tract of land has been sold dependent upon a better offer being made, and a higher price is subsequently offered, and the vendor adjudges the said tract to the second purchaser, together with another adjoining it, and does this without fraudulent intent; he will not be liable to the former purchaser, even though he not only sold him what was included in the offer at a higher price, but also another tract; still, if the vendor was not guilty of fraud, the transaction with the first purchaser is at an end, for it should only be considered whether the transfer to the second purchaser was made in good faith.

Ad Dig. 18,4,8ROHGE, Bd. 16 (1875), Nr. 43, S. 150: Verpflichtungen aus dem Verkaufe eines nicht existirenden Kaufobjekts. Eigener Wechsel an eigene Ordre. Einfluß des Irrthums.Windscheid: Lehrbuch des Pandektenrechts, 7. Aufl. 1891, Bd. II, § 307, Note 5; Bd. II, § 315, Note 7.Javolenus, On Plautius, Book II. Where the vendor has no right of succession to an estate, in order to ascertain how much he should pay the purchaser, a distinction must be made, namely: where a right of succession, in fact, exists, but does not belong to the vendor, it should be appraised; but if there is no right of succession at all, with reference to which the agreement appears to have been made, the purchaser can recover from the vendor only the price which he paid, and any expenses which he incurred on account of the property.

Javolenus, On Plautius, Book II. If it was agreed upon in the sale of the succession to an estate that any rights of the vendor should be sold, but that afterwards nothing should be guaranteed by him, and even though the right of succession did not belong to the vendor, he would, nevertheless, not be liable on this account, because it was manifestly the intention that as any profit arising from the transaction would belong to the purchaser, he must also bear the risk.

Javolenus, On Plautius, Book II. Where it is not stated at the time of the sale to what extent the vendor should be liable in case of eviction, he will not be liable on this ground for more than simple damages, and for the amount of the interest of the purchaser dependent upon the nature of the action of sale.

Javolenus, On Plautius, Book II. A purchaser knew that a part of the land which he bought belonged to another. The opinion was given that he could not obtain any of the land by virtue of long possession. I think that this is true, if the purchaser was not aware what part of the land belonged to another; for if he knew that it was a certain tract of it, I have no doubt that he could obtain the remainder on the ground of long possession. 1The same rule of law applies, if a man who purchased an entire tract of land was aware that an undivided part of it belonged to someone else; for he can not only acquire that part by usucaption, but he will not be prevented from acquiring the remaining parts by long possession.

Javolenus, On Plautius, Book II. If a slave who has been manumitted by will, but is not aware that he is free, remains as part of the estate, and stipulates for money for the heir, the heirs will not be entitled to anything, provided they knew that he had been manumitted by the will, because his servitude cannot be considered lawful where he serves those who knew that he was free. This case differs from that of a freeman who, having been purchased, serves in good faith as a slave; because, in this instance, the opinion of himself and the purchaser agree as to his condition. He, however, who knows a man to be free, although he may be ignorant of his condition, cannot be held to possess him.