Meeting report

Braggs, chemistry and Leeds

[Bragg,
Lowe, Giachardi, Heath, Jones] Left to right: Charles Bragg, Alison Lowe, David Giachardi, Lady Heath, and Derry Jones

Vacation collaboration in a shed at Leeds U., 1912-1914, contributed appreciably to the science meriting the Nobel Prize for W.H. and W.L. Bragg in 1915. Although the prize was in Physics, X-ray crystal structure analysis has, of course, influenced sciences from mineralogy to medicine. On July 1, 2003, the UK Royal Soc. of Chemistry (RSC) recognized the contribution to chemistry of the Braggs' achievement by making the Leeds site a National Historic Chemical Landmark. WLB's daughter, Margaret (Lady Heath) recalled WLB anecdotes and unveiled a plaque in the presence of the chemist's grandson, Charles Bragg, and of the University's Vice Chancellor (but not the Chancellor, who is unrelated, Melvin Bragg).

[Giachardi, Cruickshank] D. Giachardi and DWJ Cruickshank

Durward Cruickshank, whose crystallographic career began under E.G. Cox at Leeds (1946-1962), gave a fascinating survey of the 1912-1914 researches and their continuing influence on chemical sciences. Pouring salt and sugar, he noted the long interval between their structure determinations and marveled that WLB, who had determined the NaCl structure in 1913, could draw the lysozyme structure by his 75th birthday in 1965. Durward highlighted how, by the summer of 1912, WHB (1862-1942) and WLB (1890-1970) were well prepared to respond to the discovery of X-ray diffraction by Friedrich Knipping and von Laue. WHB, a mathematician turned physicist, without research training per se, began original research (contrast demonstration and confirmatory experiments) in radioactivity in Australia only at the age of 42. By the time he was Physics Professor at Leeds, he was experienced in instrumental manipulation and experimental design and was well-versed in X-ray tubes and the ionization chamber. WLB, a graduate of both Adelaide and Cambridge by age 22, knew the work of W. Barlow on symmetry and the chemist W.J. Pope on how crystals might be structured internally. No doubt this helped him devise the simplifying concept of X-ray reflection in 1912. Father and son then worked ferociously 1913-1914 to determine crystal structures with the ionization spectrometer.

Leeds also figured in the subsequent careers of three of WHB's 1920s collaborators at London's Royal Institution: W.T. Astbury, Kathleen (then Yardley) Lonsdale (who spent 1927-1929 at Leeds), and E.G. Cox. Mature crystallographers will know that Gordon Cox assembled (1945-1957) at Leeds a famous chemical crystallography group whose faculty included George Jeffrey (before Pittsburgh), Durward Cruickshank, Mary Truter, Peter Wheatley, Norman Hartshorne (microscopy), Geoffrey Pringle, and John Robertson. Maturer crystallographers still may recall that in 1946 Leeds had four X-ray groups under: Cox in Chemistry; G.W. Brindley (clay minerals, previously with WLB at Manchester, later at Penn. State) in Physics; W.T. Astbury on wool proteins in Biomolecular Structure; and H.J. Woods on fibres in Textile Physics.

Durward's masterly survey helped chemists celebrate Leeds University's greatest achievement and the youngest Nobel Laureate.

Derry W. Jones