According to our honoured custom I preface this annual address by references to those of our Fellows whom death has taken from us during the past year. Arthur Hutchinson (1866-1937), Emeritus Professor of Mineralogy in the University of Cambridge and lately Master of Pembroke College, was elected a Fellow of the Royal Society in 1922. He had served on the Council from 1932 to 1934 and was a Vice-President for the year 1933-4. While still young Hutchinson made a name for himself by brilliant researches on the chemistry and crystallography of stokesite and other minerals. He devised a stereographic projector and a slide rule which are much used by students of crystallography: and he was skilful in the construction of crystal models and lecture-room apparatus. As a teacher in the University of Cambridge he was highly successful: though it was not until 1926 that he became Professor of Mineralogy, his work had long been of professorial standing. When the use of X-ray methods from 1914 onwards opened up a new crystal science, he at once attached himself to its ways and aided its development. He designed his instruments afresh. He devoted his energies towards the organization of his Department to meet the altered needs in teaching and research. He was a devoted servant to Science, an excellent investigator, an able teacher and one of the kindest and most loyal of friends.