CRYSTALLOGRAPHY

Wairarapa Times-Age, 16 February 1939, Page 11

CRYSTALLOGRAPHY

NEW EDINBURGH LECTURESHIP. ■ > — X-RAY EXPLORATION. I The possible uses of X-ray crystallography in determining the atomic structure of complex substances such as insulin, the chemical composition of which was not at present known, were described by Dr C. A. Beevers, Dewar Research Fellow, in his inaugural lecture in the chemistry department of Edinburgh University, where Dr Beevers has been appointed lecturer in crystallography. Sir William Bragg, 0.M., K.8.E., president of the Royal Society, presided. Principal Sir Thomas Holland said that in 1936 Lady Dewar left money, which the trustees decided to give to the University of Edinburgh. They had been asked to make out a scheme for the use of the money, and decided to reappoint a lecturer in crystallography after a lapse of years. He referred to the distinguished work carried out in crystallography by Sir William Bragg and his son. Sir William Bragg, introducing Dr Beevers, wished him well in his new appointment. Dr Beevers had collaborated very successfully with Sir William’s son, and he very much admired the work that their new lecturer was beginning in Scotland. This work was connected with many other branches of science, and it was indeed difficult to find another science into which crystallisation did not come nowadays. ANALYSIS OF INSULIN. Crystals, the lecturer pointed out, were regular arrangements of atoms, As a simple simile, he likened the 'atoms in a crystal to men on paradeone row behind another. The discovery made by Laue in Germany in 1913 of the diffraction of X-rays by passing them through a crystal enables us to investigate the detailed structure of crystals. That discovery was taken up by the Braggs, who made it much more intelligible to ordinary people than it was by Laue’s mathematical process, and who made it much more picturesque. By means of this discovery it was possible to find out the exact details of the arrangements of atoms for all kinds of subsances, provided they were crystalline. The most interesting examples at the present time were biochemical substances like insulin, of which the chemical composition was not known. Dr Beevers pointed out that it was only a matter of further development in technique before they would be able to make X-ray analysis applicable to complex structures such as insulin. He explained that they had a special X-ray set for the purposes of determining the structure of crystals —the only one of its kind in Scotland—the chief difference between it and the hospital type of X-ray outfit being that the beam produced from a hospital installation was wide, but the beam produced in this special set was a thin, intense pencil. He also explained the use of the Fourier synthesis in working out crystal structures, and indicated that one of the main points in his researches was the simplification, as far as possible, of the calculations involved.