"During the period in which the theory of phlogiston reached its zenith, four names stand out in bold relief. They are those of Joseph Black (1728–99), Henry Cavendish (1731–1810), Karl Wilhelm Scheele (1742–86), and Joseph Priestley (1733–1804). Of these men the last three were steadfast adherents of the theory, while Black seems to have been indifferent, devoting himself to his researches and placing his own interpretation upon his results."