Ad Dig. 1,3,39Windscheid: Lehrbuch des Pandektenrechts, 7. Aufl. 1891, Bd. I, § 16, Note 3.Celsus, Digest, Book XXIII. That which has in the first place been introduced, not by any rule but through error, and has afterwards been confirmed by custom, shall not prevail in other similar cases.

Celsus, Digest, Book XXIII. Where a party in good faith purchases land which did not belong to the vendor, and uses a right of way which is attached to the land, the right will be retained; and this also will be the case even if he is a possessor by sufferance, or, after the owner has been ejected by force; for where land is invested with a certain character so that it is held in possession in that condition, the right is not lost; and it does not make any difference whether or not the party in possession, who holds it as it is, does so legally or not. Wherefore, it may be stated even more positively, that if water flows through a channel of itself, the right of conducting it there is retained; which opinion was very properly held by Sabinus, and is mentioned in Neratius in the Fourth Book of Parchments.

Celsus, Digest, Book XXIII. What I possess in my own name I can possess in that of another. For I do not change the title to my possession when I hold it through another, but I cease to possess the property, and I render him possessor by my own act. It is not the same thing to possess personally and to possess in the name of another; for he possesses in whose name possession is held. A representative lends his agency to the possession of another. 1If you deliver property to an insane person whom you think is in the enjoyment of his faculties, for the reason that, while in your presence he appeared to be quiet, and have his mind unclouded, although he will not obtain possession, you will “lose it. For it is sufficient to have relinquished possession, even if you did not legally transfer it, as it would be absurd to say that anyone did not intend to relinquish it unless he legally transferred it; and, indeed, it is because he thinks he transferred it that he manifests his intention to give possession. 2Ad Dig. 41,2,18,2ROHGE, Bd. 14 (1875), Nr. 40, S. 105: Erwerb des Pfandrechts durch Unterbringung der Objecte in dem vom Gläubiger gemietheten Lokale.If I order the vendor, of whom I have made a purchase, to deliver the article at my house, it is certain that I possess the property, even if no one has yet touched it. Or, if the vendor should show me from my tower a neighboring tract of land of which he says that he delivers me the possession, I begin to possess the said land, and just as if I had placed my foot within the boundaries of the same. 3If, when I am on one side of my land, some other person enters upon the opposite side, with the intention of clandestinely obtaining possession, I am not considered to have immediately lost possession, as I can easily eject him from the premises, as soon as I am informed of his act. 4Again, if an army enters upon land with great violence, it will only gain possession of that portion which it occupied.