The history of how lithium came into existence raises multiple questions about the place that detection, isolation and the determination of properties hold in an element’s discovery story. Historians of science rarely link Humphry Davy and William Thomas Brande, successive Professors of Chemistry at the Royal Institution, with the element lithium, but both have a part to play in its story.

Lithium’s first detection (in the mineral petalite) is generally credited to Johan August Arfwedson. Information related to “the new alkali lately discovered in Sweden” was published in the Quarterly Journal of Science (edited by Brande) in London in July 1818. This reported that Davy had submitted lithia to electrolysis and that it decomposed with the same phenomena as potassium and sodium. In 1819, writing in his textbook, Manual of Chemistry, Brande set out the process for isolating lithium, recounted Arfwedson’s work and Davy’s electrolysis but only named the former. This has apparently led various sources including John Emsley’s The Elements and Wikipedia to credit the isolation of lithium to Brande. Somewhat surprisingly, given Davy’s reputation for discovering or isolating a number of elements and his tendency for self-publicity, he never sought to add lithium to his list of elements.

This paper addresses the mysterious issues raised by considering lithium’s ‘discovery’, with a particular focus on Davy, Brande and the Royal Institution and how their contributions were disseminated in the British chemical community. It also explores how stories of discovery can exclude or exaggerate as they evolve over time.

It has become increasingly difficult to discover chemical elements. Whether this is because science approaches the endpoint of this endeavour or because of experimental limitations, this difficulty affects how we conceive of element discovery. In light of this, I argue that the concept of element discovery has undergone a shift and that latest attempts to offer specific criteria for an element’s discovery have rendered the concept flexible and fluid. To support this, I present how element discovery has been construed throughout the past decades. I show that what it means to discover elements is not understood in the same way today as it was in the past, resulting in a much more fluid concept. This in turn prompts us to revise the role philosophers assign to discoveries in science. In fact, the adoption of a fluid concept of element discovery prompts pressing questions about standard philosophical issues around scientific discovery. This includes how philosophers should construe the role of discoveries in the evaluation of scientific advances.

Neither a proto-science nor a solely esoteric discipline, alchemy found itself for the first time at the centre of a complex public debate of a scientific, historical and philosophical nature in the aftermath of the late 18th-century Chemical Revolution. Of relevance to a correct reconstruction and contextualisation of this debate is the isolation and analysis of trends and discoveries within the chemical research of the time, which provided the occasion for the resurgence (during the first half of the 19th century) of the best-known alchemical topic, the transmutation of metals.
There were two prerequisites for the transmutability of metals to become once again a scientifically acceptable subject of research from the 1810s: new hypotheses concerning the mutual reducibility of certain elements, such as those of integer multiples and protyle put forward by the British chemist and physician William Prout (1785 - 1850), and the experimental confirmation that chemical compounds with the same percentage composition could be substances with very different properties, i.e. the discovery of isomerism and allotropy. This paper aims to illustrate how these premises were exploited to legitimise the transmutation hypothesis.