100 YEARS AGO

A series of tables, showing the differences between Greenwich mean time and the civil times used in various parts of the world, compiled by Prof. John Milne, F.R.S., is published in the February number of the Geographical Journal. The names of places in the tables are arranged in alphabetical order, and the amount by which the time used at each is fast or slow of Greenwich mean time is indicated. ⃛ It is pointed out that the Chinese at most places use an approximate apparent solar time, obtained from sun-dials. At Tientsin the civil time is determined by the municipal chronometer, which, however, has sometimes been known to have an error of three minutes. The Persians keep sun time, watches being set at sunset. In Teheran there is a midday gun fired by the time shown on a sun-dial. But a few minutes makes no difference in Persia; the railway trains start when full or when required, and Persian telegraphists do not give time of issue or receipt of telegrams.

From Nature9 February 1899.

50 YEARS AGO

The nucleic acids and their derivatives are fundamental constituents of biological systems; but until recently workers have lacked precise micro methods for their study. Vischer and Chargaff, and recently Hotchkiss and also Reichard, have shown that partition chromatography may be used to separate and characterize certain derivatives. The methods employed by these workers to detect the spots on the chromatograms were, however, either limited in their scope or necessitated the analysis of a large number of fractions selected arbitrarily from the columns. We have approached this problem in a different way. Purine and pyrimidine derivatives are characterized by an intense ultra-violet light absorption in the region of 2650 A., and they can be detected in amounts of 10 μgm. or less by a simple photographic technique. — Roy Markham, John D. Smith

From Nature 12 February 1949.

Many more extracts like these can be found in ABedside Nature: Genius and Eccentricity in Science, 1869-1953, a 266-page book edited by Walter Gratzer. Contact Lisa O'Rourke. e-mail: l.orourke@nature.com