Keir was a significant member of the group who kick-started the Industrial Revolution, and established the world’s first soap factory. He and Darwin, a close lifelong friend (he suggested helpful improvements to Darwin’s poetry), met as students in Edinburgh; through Darwin he met Wedgwood and other Lunar Society members. Among those who became good friends, he worked closely with Priestley, managed Boulton and Watt’s business (unpaid) while they were away, loved Small affectionately, and wrote a biography of Day. Black and Berthollet were among his correspondents. Davy described him as both amiable and great.