The Same, On Quintus Mucius, Book XXXVII. Where two joint-promisors owe the same sum of money, and one of them is released from his obligation through having forfeited his civil rights, the other will not be released. For it makes a great deal of difference whether the money itself is paid, or the person is released; since when one is released and the obligation continues to exist, the other will remain liable; therefore, if one of them has been excluded from water and fire, the surety of the other will afterwards be liable.

Pomponius, On Quintus Mucius, Book XXXVII. The same rule applies to clothing.

Pomponius, On Quintus Mucius, Book XXVII. The right of postliminium exists both in war and in peace. 1In war, when those who are our enemies seize one of us, and take him within their fortifications, for if he returns during the same war, he will have the right of postliminium; that is to say, all his rights will be restored to him, just as if he had not been captured. Before he is taken into the fortifications of the enemy, he remains a citizen, and he is understood to have returned if he comes to our friends, or within our defences. 2The right of postliminium is also granted in time of peace; for if there is a nation between which and us there exists neither friendship, hospitality, nor any bond of attachment, it indeed is not our enemy. Anything, however, which belongs to us, and passes under its control becomes its property, and any freeman of our people taken in captivity by such a nation becomes its slave. The same rule applies if anything belonging to the said nation comes into our hands, and therefore the right of postliminium is conceded in this instance. 3If a captive has been manumitted by us, and returns to his friends, he is only understood to have returned under the right of postliminium, if he prefers to go to them, rather than to remain in our country. And, therefore, in the case of Attilius Regulus, whom the Carthaginians sent to Rome, it was decided that he did not return under the right of postliminium, because he had sworn that he would return to Carthage, and did not have the intention of remaining at Rome. Hence, when a law was enacted with reference to a certain interpreter, named Menander, who, after having been manumitted while in our hands and sent back to his people, providing that he should remain a Roman citizen, this was not considered necessary, for if he had the intention of remaining with his own relatives, he would cease to be a citizen; but if he expected to return he would still remain a citizen, and therefore the law was superfluous.

Pomponius, On Quintus Mucius, Book XXXVII. When anyone strikes the envoy of our enemy, he is considered to be guilty of an act against the Law of Nations, because envoys are considered sacred. Therefore, if any ambassadors of a nation with whom we are at war are with us, it has been established that they are free to remain; for this is in conformity with the Law of Nations. Hence, Quintus Mucius held that anyone who struck an ambassador is usually surrendered to the enemy of whom he was the representative. The question arose, if the enemy did not receive the offender when he was sent to them, whether he would remain a Roman citizen. Some authorities think that he would remain such, and others are of the contrary opinion, because where a people have once ordered anyone to be surrendered he is considered to have been deprived of citizenship, just as is the case where anyone is forbidden fire and water. It seems that Publius Mucius was also of this opinion. This question was thoroughly discussed in the case of Hostilius Mancinus, whom the Numantians would not receive when he was surrendered to them; and, on this account, a law was subsequently enacted to enable him to remain a Roman citizen, and he is said to have even held the office of Prætor.