What, precisely, is `salt'? It is a certainwhite, solid, crystalline, material, alsocalled sodium chloride. Does any of that solidwhite stuff exist in the sea? – Clearly not.One can make salt from sea water easily enough,but that fact does not establish thatsalt, as such, is present in brine. (Paper andink can be made into a novel – but no novelactually exists in a stack of blank paper witha vial of ink close by.) When salt dissolves inwater, what is present is no (...) longer `salt' butrather a collection of hydrated sodium cationsand chloride anions, neither of which isprecisely salt, nor is the collection. Theaqueous material in brine is also significantlydifferent from pure water. Salt may beconsidered to be present in seawater, but onlyin a more or less vague `potential' way.Actually, there is no salt in the sea. In bothancient and modern treatments of otherimportant chemical concepts, including thenotions of `element', related complication,especially polysemy (terms with multiplemeanings), also occurs.In a recent paper, Paul Needham discussed the(predicable) properties of chemical substances,phases, and solutions. He provided a valuablecharacterization of cases in which severalquantities occupy the same space. He alsoconcluded that solution properties are not`intensive', because solvent and solute do nothave parts in common. He tacitly assumed thatingredients are not altered by their inclusionin a solution. This may be the case in somespecial cases (deutero-benzene dissolved inbenzene, say) but is not true in general – andcertainly does not apply to the case of brine,which Needham used as an example – since theions that exist in the solution, and also theaqueous material there, are quite differentfrom the pure ingredients used in making thesolution. An adequate theory of wholes andparts (mereology) must take into account thatwhen individuals enter combinations ofinteresting sorts they no longer are the verysame individuals that existed prior to thecomposition. It appears that no such formaltheory now actually exists. (shrink)

What are the criteria determining the individuation of chemical kinds? Recent philosophical discussion, which puts too much emphasis on microstructure, seems to presuppose a reductionist conception not motivated by the scientific facts. The present article traces the development of the traditional notion of a substance with the rise of modern chemistry from the end of the 18th century with a view to correcting this speculative distortion.

This article is a translation into english of a lecture given by paneth in 1931. The content of the work is described by the section titles: (1) the need for epistemological clarification of the fundamental concepts of chemistry, (2) the concept of substance in chemistry, (3) the epistemological standpoint of the ancient atomists, (4) the epistemological position of the concept of element introduced by lavoisier, (5) the double meaning of the chemical concept of element: 'basic substance' and 'simple substance', And (...) (6) the double meaning of other chemical concepts. Sections (4)-(6) are published in the following number of this journal. (staff). (shrink)

This article is a translation into english of a lecture given by paneth in 1931. The content of the work is described by the section titles: (1) the need for epistemological clarification of the fundamental concepts of chemistry, (2) the concept of substance in chemistry, (3) the epistemological standpoint of the ancient atomists, (4) the epistemological position of the concept of element introduced by lavoisier, (5) the double meaning of the chemical concept of element: 'basic substance' and 'simple substance', And (...) (6) the double meaning of other chemical concepts. Sections (4)-(6) are published in the following number of this journal. (staff). (shrink)

The bulk of Duhem's writing which bears on the understanding of mixtures suggests he adopted an Aristotelian position which he opposed only to the atomic view. A third view from antiquity-that of the Stoics-seems not to be taken into account. But his lines of thought are not always as explicit as could be wished. The Stoic view is considered here from a perspective which Duhem might well have adopted. This provides a background against which his somewhat unorthodox Aristotelianism might be (...) understood. (shrink)