SADLER, MICHAEL THOMAS (1780–1835), English, social reformer and economist, was born at Snelston, Derbyshire, on the 3rd of January 1780. Settling down in business in Leeds in 1800, he early took an active part. in political life, devoting himself particularly to the administration of the poor law. In 1828 he wrote Ireland: its Evils and their Remedies, in which he advocated a poor-law, and a tax on absenteeism. He also took a share in the Malthusian controversy, writing The Law of Population: a Treatise in Disproof of the Super-fecundity of Human Beings and developing the Real Principle of their Increase (1830). He entered parliament in 1829 as member for Newark, and devoted his efforts to questions of social reform. He took a leading part in the agitation for the prevention of child labour in factories—he was chairman of, the committee appointed to inquire into the subject. He contested Leeds after the Reform Bill of 1832 (Aldborough, for which 'he had sat after Newark, being deprived of its member), but was defeated by Macaulay. In 1834 he was unsuccessful at Huddersfield, and failing health prevented any further attempts to re-enter parliament. He settled down in Belfast, where his firm had business interests, and died at New Lodge on the 29th of July 1835.
See R. B. Seeley, Memoirs of M. T. Sadler (1842).