A dissertation on the following subject: what causes principally contribute to render a nation populous? and what effect has the populousness of a nation on its trade? : Being one of those to which were adjudged the prizes given by the Right Honourable the Lord Viscount Townshend to the University of Cambridge, in the year 1756: and read there in the public schools on Friday, July the 2d. By William Bell, M.A. fellow of Magdalen College.