JF Ptak Science Books Quick Post
August Hofmann (a German organic chemist of high calibre, 1818-1892) made this presentation1 to the Royal Institution in 1865, and it is one in which hand-made three-dimensional models of molecules2 are used for one of the first times for public demonstration. (He actually made parts of it in different lectures, that is, but I have not yet been able to compare the two.) The models aren't quite three-dimensional, as Hofmann arranged them so that they would have at least 3-D molecules though their arrangement in space was veyry much liek they would appear on a piece of paper. (This might be a bit off, and the molecules were all the same size, but the colors he employed to represent molecules are still being used: black/carbon, yellow/sulphur, white/hydrogen, blue/nitrogen, red/oxygen, green/chlorine.
Notes:
1. HOFMANN, August Wilhelm. “On the Combining Power of Atoms”, in three parts, all in The Chemical News, October 5, 1865, pp 166-169; October 13, 1865, pp 175-179; and in October 20, 1865, pp 187-190.
2. The idea of molecules goes back 2000 years, to Empedocles, Leucippus, Democritus, and Epicurus. It should be noted I guess that the modern idea of the world (mostly?) owes itself to an 1873 article in Nature by James Clerk Maxwell. He titled the paper, well, "Molecules", and this is how he defined his terms: "An atom is a body which cannot be cut in two; a molecule is the smallest possible portion of a particular substance."
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