Jactus lapilli
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
The throwing down of a stone. One of the modes, under the civll law, of interrupting prescription. Where one person was building on another's ground, and in this way acquiring a right by usucapto, the true owner challenged the intrusion and interrupted the prescriptive right by throwing down one of the stones of the building bsfore witnesses called for the purpose. Tray. Lat. Max.