Copy of a letter addressed to the Right Honourable the Chancellor of the Exchequer : and the substance of a speech of Mr. Joseph Hume, on the third reading of the bill (Friday, July 21, 1812,) for "preventing frauds and abuses in the frame-work-knitting manufacture, and in the payment of persons employed therein," in which the impolicy of attempting by legislative enactments to regulate or controul the employment of capital and the price of labour is clearly shown.