Most historians have ruled out the possibility that John Dalton was influenced by the theories of atomists William and Bryan Higgins, as well as William Austin, in developing his first table of atomic weights on 6 September 1803. I review and evaluate the case to be made for the influence of each scientist on Dalton. Contrary to prevailing views, I raise new Daltonian doubts, especially for Bryan Higgins.

William Higgins is primarily remembered for his claims to have developed the principles of the atomic theory before John Dalton. Why did Higgins, who did not issue a single word in print on the atomic theory for 25 years after his 1789 book A Comparative View, suddenly claim priority in 1814, and then continue to pursue his assertions against Dalton and his supporters with such vitriol? This paper argues that Higgins's delay in sending a sample of the Mooresfort meteorite to the naturalist and illustrator James Sowerby contributed to the Dublin Society's decision to split Higgins's dual professorship of chemistry and mineralogy, which led to the hiring of mineralogist Charles Giesecke. Higgins's subsequent frustrations, including an ongoing competition with Giesecke, indicate that his claims to the atomic theory were attempts to rebuild his diminished status.

During the years 1814-1819, William Higgins, an Irish chemist who worked at the Dublin Society, claimed he had anticipated John Dalton in developing the atomic theory and insinuated that Dalton was a plagiarist. This essay focuses not on William Higgins, but on his uncle Bryan Higgins, a well-known chemist of his day, who had developed his own theories of caloric and chemical combination, similar in many respects to that of Dalton. New evidence is first introduced addressing Bryan's disappearance from the scientific community after 1803. In his later years, Bryan apparently suffered from a condition resulting in a decline in his mental health, which explains why he never lodged any priority claims of his own against Dalton, or defended those of his nephew. Dalton's mention of Bryan's name in Part II of A New System of Chemical Philosophy, his laboratory notebook entries, and a fresh look at his correspondence with chemist Thomas Charles Hope indicate that Dalton adopted a Higgins-like caloric model in 1803. Together these factors provide evidence to support the argument that Dalton learned of Bryan's theories via a meeting he had with William Allen on 10 July 1803. Existing evidence related to the origin of the atomic theory is worthy of re-examination in light of Dalton's possible prior knowledge of Bryan's work.

No abstract

Smithson Tennant is known mainly for his discovery of osmium and iridium. This paper details Tennant's involvement with meteorites, which has received little attention by his biographers, and provides new information about his final stay in Paris. Tennant reported his analysis of the Cape of Good Hope meteorite in 1806 and received a sample of the Bendego meteorite in 1811 that was subsequently analysed by Wollaston. During Tennant's final trip to France, which began in September 1814, Berthollet presented a sample of the Limerick meteorite that he received from Tennant to the French Institute. Tennant visited Delamétherie, and an unpublished letter acquired by the author shows that he met the explorer and scientist Alexander von Humboldt. The Limerick meteorite was discussed with Delamétherie and probably with Humboldt. Evidence suggests that Tennant met the painter François Gérard and the scientists Biot, Arago, Gay-Lussac and Cuvier. The Limerick meteorite specimen that Tennant gave to Berthollet is probably Muséum National d'Histoire Naturelle sample MNHN-35, whose donor is unknown. Tennant was the first to be quoted in the scientific literature about the Limerick meteorite—more than three years before the scientist William Higgins published his account of the meteorite shower.