This is not a normal book. It is a collection of transcripts of talks that I gave between the year 2003 and now. I gave most of these talks on the spur of the moment, without making notes ahead of time. (“Impromptu” is the usual term for that dangerous way of speaking.) One of the “talks” is not a transcript, but a set of notes for a talk I never gave. Any organization or order in the talks is purely coincidental—or (...) at least it’s not all my fault. (shrink)

Immanuel Kant has built up a dualistic epistemology that seems to fit to the peculiarities of chemistry quite well. Friedrich Paneth used Kant’s concept and characterised simple and basic substances which refer to the empirical and to the transcendental world, respectively. This paper takes account of the Kantian influences in Paneth’s philosophy of chemistry, and discusses pertinent topics, like observables, atomism and realism.

Several attempts have recently been made to point to ‘the proper place’ for hydrogen in the Periodic Table of the elements. There are altogether five different types of arguments that lead to the following conclusions: hydrogen should be placed in group 1, above lithium; hydrogen should be placed in group 17, above fluorine; hydrogen is to be placed in group 14, above carbon; hydrogen should be positioned above both lithium and fluorine and hydrogen should be treated as a stand-alone element, (...) in the center of the Periodic Table. Although all proposals are based on arguments, not all of them sound equally convincing. An attempt is made, after critical reexamination of the arguments offered, to hopefully point to the best possible choice for the position of hydrogen. A few words are also mentioned on the structure of the Periodic Table and the attempts to reorganize it. (shrink)

A lively philosophical debate has lately arisen over the nature of elementhood in chemistry. Two different senses in which the technical term ELEMENT is currently in use by chemists have been identified, leaving chemistry open to the logical fallacy of equivocation. This paper introduces a third, more elemental candidate: the high-enthalpy short-lived unbonded atom. An enthalpy index based on free-atoms-as-elements is established, whereby one can monitor the degree to which an atom’s spin-based attractive force is implemented exo-enthalpically when the atom (...) binds chemically to others. Enthalpy indexing shows that the strength of an atom’s attractive force is proportional to its spin angular momentum. Vibrational spectroscopy shows that the force varies inversely as the fourth power of the inter-atom distance. Both features differentiate the chemical force from the stronger electromagnetic force and from the weaker Van der Waals force. (shrink)