Janet is known almost exclusively for his left-step periodic table (LSPT). A study of his writings shows him to have been a highly creative thinker and a brilliant draftsman. His approach was primarily arithmetic-geometric, but it led him to anticipate the discovery of deuterium, helium-3, transuranian elements, antimatter and energy from nuclear fusion. He recognized the (n + ℓ) rule well before Madelung and correctly placed the actinides. His controversial treatment of helium at the head of the alkaline earth elements (...) might be less provocative if his system were taken in one of its spiral representations. (shrink)

There is now a considerable body of published work on the epistemology of modern chemistry, especially with regard to the nature of quantum chemistry. In addition, the question of the metaphysical underpinnings of chemistry has received a good deal of attention. The present article concentrates on metaphysical considerations including the question of whether elements and groups of elements are natural kinds. It is also argued that an appeal to the metaphysical nature of elements can help clarify the re-emerging controversies among (...) chemists regarding the placement of the elements hydrogen and helium in the periodic system and the question of whether there exists a best form of the periodic table. (shrink)

Throughout the history of philosophy, chemical concepts and theories have appeared in the work of philosophers, both as examples and as topics of discussion in their own right, and scientists themselves have often engaged with theoretical, conceptual, and methodological issues that fall within what one would now recognize as philosophy of chemistry. This chapter offers a summary of the history of philosophy of chemistry since Kant, alongside a critical examination of why chemistry has been relegated to the sidelines so frequently (...) in recent philosophy of science. This history offers a unique vantage point from which to consider the interests and assumptions, often implicit, that underlie 20th-century philosophy's view of what science is or perhaps should be. These include the inheritance of logical positivism and empiricism, with its particular focus on theories expressed in the language of mathematics and understood as axiomatic systems, and the widespread acceptance of reductionist views of theoretical explanation. Against this background, much of chemistry disappears. Being perhaps too grounded in laboratory and experimental practice, and often practical in its aims and correspondingly pragmatic in its methods, chemical science seldom resembles an orderly top-down enterprise from fundamental theoretical principles. Many of its central "theories," like molecular structure, are expressed in systems of visual representation rather than mathematical equations. This chapter is further is devoted to brief discussions of historical individuals, both chemists and philosophers, whose work is relevant for contemporary philosophy of chemistry. © 2012 Elsevier B.V. All rights reserved. (shrink)