Margaret Cavendish, Duchess of Newcastle-upon-Tyne, was an English aristocrat, writer, and scientist who took part in many important scientific debates. Her works included Observations upon Experimental Philosophy and Grounds of Natural Philosophy.
Thomas Day was the first Lunar Society figure publicly to attack slavery. In 1773 he read a newspaper report about a slave working for a ship’s captain who fell in love with a white female servant. The slave ran away to be christened, so that he could marry her. Recaptured, he was locked up in a boat on the Thames and shot himself in the head. Day was moved by the experience to compose a lengthy poem, The Dying Negro, one of the first works of propaganda against slavery.