The merchant's public counting-house: or, New Mercantile Institution: wherein is shewn, the necessity of young merchants being bred to trade with greater advantages than they usually are. With a practicable plan for that purpose : Also some remarks on the benefit of this institution to the young nobility and gentry, and such who are intended for the study of the law. By Malachy Postlethwayt, Esq; the plan to be carried into execution by him and company.