from
Bouvier's Law Dictionary, Revised 6th Ed (1856)
RES MANCIPI, Rom. civ. law. Those things which might be sold and alienated,
or the property of them transferred from one person to another. The division
of things in to res mancipi and res nec mancipi, was one of ancient origin,
and it continued to a late period in the empire. Res mancipi (Ulph. Frag.
xix.) are praedia in italico solo, both rustic and urban also, jura
rusticorum praediorum or servitutes, as via, iter, aquaeductus; also slaves,
and four-footed animals, as oxen, horses, &c., qum collo dorsove domantur.
Smith, Diet. Gr. and Rom. Antiq. To this list, may be added children of
Roman parents, who were, according to the old law, res mancipi. The
distinction between res mancipi and nec mancipi was abolished by Justinian
in his code. Id.; Coop. Ins. 442.