Dictionary.net

A system of customs acknowledged and taken notice of by all commercial nations; and those customs constitute a part of the general law of the land; and being a part of that law their existence cannot be proved by witnesses, but the judges are bound to take notice of them ex officio. See Beawes' Lex Mercatoria Rediviva; Caines' Lex Mercatoria Americana; Com. Dig. Merchant, D; Chit. Comm. Law; Pardess. Droit Commercial; Collection des Lois Maritimes antÇrieure au dix hutiäme siäcle, par Dupin; Capmany, Costumbres Maritimas; II Consolato del Mare; Us et Coutumes de la Mer; Piantandia, Della Giurisprudenze Maritina Commerciale, Antica e Moderna; Valin, Commentaire sur l'Ordonnance de la Marine, du Mois d'Aoñt, 1681; Boulay-Paty, Dr. Comm.; Boucher, Institutions au Droit Maritime.