should tend to simplify the plan of the custom-houses, and render them of easier access; the exposition of the prejudicial influence which the intermediate traffic of Buenos-Ayres has on the commerce of Peru; the project proposed in the year 1739, and latterly renewed, of rendering quicksilver a branch of free trade, &c. &c.; which compose the fourth and last part, are great conceptions, which realize, in the present production, the elevated views the author entertained when he engaged in this very useful labour.