Lat. In Roman law. A certaln ceremony or formal process anciently required to be performed, to perfect the sale or conveyance of res mancipi, (land, houses, slaves, horses, or cattle.) The parties were present, (vendor and vendee,) with five witnesses and a person called “libripens,” who held a balance or scales. A set form of ‘words was repeated on either side, indicative ef transfer of ownership, and certain prescribed gestures performed, and the vendee then struck the scales with a piece of copper, thereby symbolizing the payment, or weighing out, of the stipulated price.