Oct 5th 2011, 16:22 by The Economist online
The changing chemical affinities of the Nobel Committee
ALFRED NOBEL, himself a chemist, founded his prizes in the late 19th century, when scientific excitement centred on chemistry. Boffins were busily filling in the blanks in the periodic table and probing unknown atomic phenomena (like radioactivity and bonding). Little wonder, then, that at the start of the 20th century most of the Nobel prizes in the discipline went to these and other discoveries under the broad label of physical chemistry. Soon, however, chemists reached a point where further advances became the province of chemical physics, rather than physical chemistry. As our chart shows, topics like the nature of organic compounds and of biological substances and processes grew more prominent. (Where the winning work straddled two categories, we ascribed half a prize to each.) The trend towards squishiness moved into reverse in the last two decades of the 20th century, however, in part because of developments in physics which yielded precision devices like the scanning-tunnelling microscope that permitted chemists to study the structure of chemical compounds close up. The 21st century, meanwhile, has again been dominated by mushier matters. Until this year's prize, that is. On October 5th it was awarded to Daniel Shechtman for the discovery of a new type of atomic lattice called quasicrystals—a discovery that, it must be remembered, was first reported in 1984 in Physical Review Letters, the world's leading physics journal.