100 YEARS AGO

Some experiments have recently been made to test whether the radio-activity of radium is influenced by the continuous bombardment to which it is subjected by its own radiations. In an article in this Journal on radium (April 30, 1903) Prof. J. J. Thomson suggested that the radio-activity of radium may possibly depend upon its degree of concentration, and that a given quantity of radium, diffused through a mass of pitchblende, may be less than when concentrated in a small mass. In order to test this point, measurements of the radio-activity of radium bromide were made when in the solid state and when diffused throughout the mass of a solution more than a thousand times the volume occupied by the radium compound... This experiment shows that, over the range investigated, the radio-activity of radium is not influenced by its own intense radiations. E. Rutherford

From Nature 7 January 1904.

50 YEARS AGO

During September 21–25, 1953, a conference was held by invitation of Prof. Linus Pauling at the California Institute of Technology in Pasadena, to discuss progress in the X-ray studies of the structure of proteins (and to a lesser extent of nucleic acids). The last conference of this kind was that arranged by the Royal Society and held in London during May 1952; it had been the first to include a full-scale discussion of the new polypeptide chain configurations proposed by Pauling and Corey, especially the α-helix... The most general and fundamental concept underlying the discussions was that helical arrangements are at the basis of many important biological structures, either at the atomic level as a type of configuration for long-chain molecules, or at the molecular level as a way in which larger units of structure may naturally aggregate. Although a helical model had been proposed for the polypeptide chain by H. S. Taylor as early as 1941, ... it cannot be said that the helix as a structural principle had entered into the fundamentals of our thinking up to the time of the Royal Society conference: indeed on that occasion there was strong disagreement as to the existence of helical chains. The Pasadena conference revealed that the helix has now come into its own with a vengeance; finding helices is a game played by nearly everyone in the field. J. C. Kendrew

From Nature 9 January 1954.