phlogiston theory. In typical Priestley fashion, he prefaced the paper with a history of the study of respiration. A year later, clearly influenced by Priestley, Lavoisier was also discussing respiration at the Académie des sciences. Lavoisier's work began the long train of discovery that produced papers on oxygen respiration and culminated in the overthrow of phlogiston theory and the establishment of modern chemistry. Around 1779 Priestley and Shelburne – soon to be the 1st Marquess of Landsdowne – had a rupture, the precise reasons for which remain unclear. Shelburne blamed Priestley's health, while Priestley claimed Shelburne had no further use for him. Some contemporaries speculated that Priestley's outspokenness had hurt Shelburne's political career. Schofield argues that the most likely reason was Shelburne's recent marriage to Louisa Fitzpatrick—apparently, she did not like the Priestleys. Although Priestley considered moving to America, he eventually accepted Birmingham New Meeting's offer to be their minister. Both Priestley and Shelburne's families upheld their Unitarian faith for generations. In December 2013, it was reported that Sir Christopher Bullock – a direct descendant of Shelburne's brother, Thomas Fitzmaurice (MP) – had married his wife, Lady Bullock, née Barbara May Lupton, at London's Unitarian Essex Church in 1917. Barbara Lupton was the second cousin of Olive Middleton, née Lupton, the great-grandmother of Catherine, Duchess of Cambridge. In 1914, Olive and Noel Middleton had married at Leeds' Mill Hill Chapel, which Priestley, as its minister, had once guided towards Unitarianism. Birmingham (1780–1791) In 1780 the Priestleys moved to Birmingham and spent a happy decade surrounded by old friends, until they were forced to flee in 1791 by religiously motivated mob violence in what became known as the Priestley Riots. Priestley accepted the ministerial position at New Meeting on the condition that he be required to preach and teach only on Sundays, so that he would have time for his writing and scientific experiments. As in Leeds, Priestley established classes for the youth of his parish and by 1781, he was teaching 150 students. Because Priestley's New Meeting salary was only 100 guineas, friends and patrons donated money and goods to help continue his investigations. He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1782. Chemical Revolution Many of the friends that Priestley made in Birmingham were members of the Lunar Society, a group of manufacturers, inventors, and natural philosophers who assembled monthly to