Rom. civ. law. Viewed as to its object and legal effect, nexum was either the transfer of the ownership of a thing or the transfer of a thing to a creditor as a security. Accordingly in one sense nexum included mancipium, in another sense mancipium and nexum are opposed in the same way in which sale and mortgage or pledge are opposed. The formal part of both transactions consisted in a transfer per Des et libram. The person who became nexus by the effect of a nexum placed himself in a servile condition, not becoming a slave, his ingenuitas being only in suspense, and was said nexum inire. The phrases nexi datio and nexi liberatio respectively express the contracting and the release from the obligation.
The Roman law, as to the payment of borrowed money, was very strict. A curious passage of Gellius gives us the ancient mode of legal procedure in the case of debt as fixed by the Twelve Tables. If the debtor admitted the debt, or bad been condemned in the amount of the debt by a judex, he had thirty days allowed him for payment. At the expiration of this time he was liable to the manus injectio, and ultimately to be assigned over to the creditor (addictus) by the sentence of the praetor. The creditor was required to keep him for sixty days in chains, during which time he publicly exposed the debtor, on three occassions, and proclaimed the amount of his debt. If no person released the prisoner by paying the debt, the creditor might sell him as a slave or put him to death. If there were several debtors, the letter of the law allowed them to cut the debtor in pieces and take their share of his body in proportion to their debt. Gellius says that there was no instance of a creditor ever having adopted this extreme mode of satisfying his debt. But the creditor might treat the debtor as a slave and compel him to work out his debt, and the treatment was often very severe. In this passage Gellius does not speak of nexi but only of addicti, which is sometimes alleged as evidence of the identity of nexus and addictus, but it proves no such identity. If a nexus is what he is here supposed to be, the laws of the Twelve Tables could not apply; for when a man became nexus with respect to one creditor, he could not become nexus to another; and if he became nexus to several at once, in this case the creditors must abide by their contract in taking a joint security. This law of the Twelve Tables only applied to the case of a debtor being signed over by a judicial sentence to several debtors, and it provided for a settlement of their conflicting claims. The precise condition of a nexus has, however, been a subject of much discussion among scholars.