Jean-Baptiste Say and Henry Brougham, M.P. Discover the Laffer Curve
In 1804, the English government raised the duties on sugar 20 per cent. It might have been expected, that their average product to the public exchequer would have been advanced in the same ratio; i. e. from 2,778,000l. the former amount, to 3,330,000l.: instead of which the increased duties produced but 2,537,000l.; exhibiting an absolute deficit. Speech of Henry Brougham, Esq., M. P., March 13, 1817.
This is from Jean-Baptiste Say, A Treatise on Political Economy, translated from the 4th edition, Book III, Chapter VIII.