BLACKWELL, Alexander, son of a dealer in knit-hose at Aberdeen, where he received a liberal education. He studied physic under Boerhaave at Leyden, took the degree of doctor of physic, and acquired a proficiency in the modern languages. He married the daughter of a gentleman in the neighbourhood; and, after an attempt to establish himself as a practitioner in Scotland, he went to London, where he met with no better success. He then became a corrector of the press, and at length set up a printing establishment of his own, which was carried on till 1734, when he became bankrupt. He appears to have subsisted for a considerable time after this event by the ingenuity of his wife, who published "A Curious Herbal, containing 500 cuts of the most useful Plants which are now used in the Practice of Physic, engraved on folio Copperplates after Drawings taken from the Life, by Elizabeth Blackwell; to which is added a short Description of the Plants, and their common Uses in Physic, 1739," 2 vols. folio. About the year 1740 Blackwell went to Sweden, and, renewing his intimacy with a nobleman whom he had met at the Hague, resumed the medical profession. Having laid before his Swedish Majesty a scheme for draining the fens and marshes, considerable sums were expended for that purpose under the doctor's direction. Being suspected, however, of being concerned in a plot for changing the succession to the Swedish throne, he was put to the torture; and this not producing the desired confession, he was beheaded, August 9. 1748. Soon afterwards appeared "A Genuine Copy of a Letter from a merchant in Stockholm to his correspondent in London, containing an impartial Account of Doctor Alexander Blackwell, his Plot, Trial, Character, and Behaviour, both under Examination and at the Place of Execution; together with a Copy of a Paper delivered to a Friend upon the Scaffold." Blackwell possessed good natural genius, but was flighty and conceited. His conversation, however, was facetious and agreeable; and he was allowed to have been a well-bred and accomplished gentleman.