Pomponius, On Quintus Mucius, Book XXXVIII. Where anyone commits a theft by using something which was lent to him or deposited with him, he can be compelled to account for doing so by a personal action for recovery on the ground of theft also, and this differs from the action to recover property loaned, because, even if the property had been destroyed without his malice or negligence, he will, nevertheless, be liable to a personal action for recovery; while in the action to recover property loaned he will not readily be held liable, except where he was guilty of negligence, and in an action on deposit he would not be liable at all unless malicious intent was established.

The Same, On Quintus Mucius, Book XXXVIII. He who uses property which has been lent to, or deposited with him, in a different way from that in which he was understood to receive it, not intending to do this against the consent of the owner, is not liable for theft; nor will he, under any circumstances whatsoever, be liable to an action on deposit. Will he be liable to an action on loan? The answer depends upon how far he was to blame; that is to say, whether he had reason to believe that the owner would not have permitted him to make use of the article as he did. 1Ad Dig. 47,2,77,1Windscheid: Lehrbuch des Pandektenrechts, 7. Aufl. 1891, Bd. II, § 453, Note 9.If anyone commits a theft against another, and a third party steals from him what he himself appropriated, the owner of the property can bring suit against the last thief; but the first thief cannot do so, because the interest of the owner, and not that of the first thief is involved, as the stolen property is safe. This was stated by Quintus Mucius, and is true; for although it is to the interest of the thief that the property should be safe, because he is liable to a personal action, still the party in interest can bring an action against him, if his interest is based on a good title. We do not adopt the opinion of Servius who held, if no owner of the stolen property had appeared, or should afterwards appear, that the thief would be entitled to the action of theft, for it could not then any the more be understood to belong to him who proposed to profit by it pecuniarily. Therefore, the owner will be entitled to an action for theft against both of them, and if he begins suit against one, his right to bring such an action against the other will continue to exist. The same rule applies to a personal action, for both of them are liable for different acts.