the eldeſt ſon only of the father ſhall ſucceed to his inheritance, but all the ſons alike: and that, though the anceſtor be attainted and hanged, yet the heir ſhall ſucceed to his eſtate, without any eſcheat to the lord.—Such is the cuſtom that prevails in divers antient boroughs, and therefore called borough-engliſh, that the youngeſt ſon ſhall inherit the eſtate, in preference to all his elder brothers.—Such is the cuſtom in other boroughs that a widow ſhall be intitled, for her dower, to all her huſband’s lands; whereas at the common law ſhe ſhall be endowed of one third part only.—Such alſo are the ſpecial and particular cuſtoms of manors, of which every one has more or leſs, and which bind all the copyhold-tenants that hold of the ſaid manors.—Such likewiſe is the cuſtom of holding divers inferior courts, with power of trying cauſes, in cities and trading towns; the right of holding which, when no royal grant can be ſhewn, depends entirely upon immemorial and eſtabliſhed uſage.—Such, laſtly, are many particular cuſtoms within the city of London, with regard to trade, apprentices, widows, orphans, and a variety of other matters. All theſe are contrary to the general law of the land, and are good only by ſpecial uſage, though the cuſtoms of London are alſo confirmed by act of parliament[1].
To this head may moſt properly be referred a particular ſyſtem of cuſtoms uſed only among one ſet of the king’s ſubjects, called the cuſtom of merchants or lex mercatoria: which, however different from the general rules of the common law, is yet ingrafted into it, and made a part of it[2]; being allowed, for the benefit of trade, to be of the utmoſt validity in all commercial tranſactions: for it is a maxim of law, that “cuilibet in ſua arte credendum eſt.”
The rules relating to particular cuſtoms regard either the proof of their exiſtence; their legality when proved; or their uſual method of allowance. And firſt we will conſider the rules of proof.
