The present state of the manufacture of salt explained; and a new mode suggested of refining British salt, so as to render it equal, or superior to the finest foreign salt : To which is subjoined, a plan for abolishing the present duties and restrictions on the manufacture of salt, and for substituting other duties, less burthensome to the subjects, more beneficial to the revenue, and better qualified to promote the trade of Great Britain. By the Earl of Dundonald.