The chemical work of Thomas Graham

• Main Author: Stanley, Michael
• Published: Open University 1979
• Subjects: 509
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.473676

Thomas Graham (1805-1869) was taught Chemistry at the Universities of Glasgow and Edinburgh by the students of Joseph Black: Thomas Thomson and Thomas Charles Hope. Graham devoted himself to Chemistry, despite opposition from his father, and became one of the foremost British chemists of his age. Essentially inductive in his research work, Graham investigated molecular movements in gases and liquids and the role of water in the constitution of acids and salts. Graham made use of analogy in directing his researches. Thus, he believed that there was a partial analogy between gaseous and liquid diffusion; both processes depended ultimately on inherent molecular motions. The chemical affinity of water for different substances connected his studies of acids and salts with the liquid state. His first chemical investigations of 1825 were concerned with the absorption of gases by liquids. Inspired by Faraday's liquefaction experiments, Graham emphasised the continuity of the states of matter and suggested an analogy between liquefaction and gaseous absorption. Heat was an important consideration in these changes of state. Graham was cautious in drawing conclusions from his experiments although he speculated imaginatively. It is possible that Graham's belief in atoms of primary matter, endowed with different, unalterable motions for each element, was conceived at the time of his first studies of gaseous diffusion. However, he slid not express this view openly until 1863. In this thesis, I have traced the development of Graham's chemical work by exploiting: unpublished manuscript material and the views of Graham and his contemporaries. Graham responded to criticisms of his work. When Berzelius dismissed the polybasic nature of the phosphoric acids, Graham countered by rejecting inorganic isomerism and he subsequently investigated polymerism. Bunsen's denial of the diffusion law and the rejection of Graham's first explanation of osmosis were spurs to further creative experimental investigations.