THE British Association holds its annual meeting in Cambridge in August 1938, and the General Committee of the Association has elected Lord Rayleigh to the presidential chair for that meeting in succession to the veteran biologist Sir Edward Poulton. Readers of NATURE need little introduction to Lord Rayleigh, whose influence on the development of physical science has been so patent and so profound. First and foremost an experimental physicist, he has his father's flair for recognizing those aspects of an experimental investigation which most need stressing, and for extracting results of fundamental importance from apparatus of simple, even primitive, type. His work on radium and the earth's heat is classic in quality, and he has elucidated many diverse, and yet related, phenomena in his studies of the aurora borealis, the light of the night sky, the green flash, and the fluorescence of mercury vapour. He has lately studied the conditions of optical contact of glass surfaces, and has investigated, by admirably simple methods, the pull required to separate, and the work done in separating, contacted surfaces. He has measured the small amount of reflection between two contacted glass surfaces, and has shown that the blackness of the black centre of the Newton's rings formed between a spherical and a plane surface is by no means perfect.