THE Quekett Microscopical Club is holding its annual conversazione on October 11 at 7.30 p.m. at Burlington House, Piccadilly, London, in the rooms of the Royal Society. Dr. Arnold Renshaw of Manchester will lecture upon the microscope in the detection of crime. It is not generally known that pieces of tissue (flesh, etc.) can be cut in slices so thin as a twenty-five-thousandth of an inch. A film made by Mr. Pittock of the Department of Anatomy and Embryology, University College, Gower Street, will be projected following Dr. Arnold Ren-shaw's lecture, showing all the stages in preparation and the actual cutting of these sections. Eighty microscopes will be set up each showing different specimens. In addition there will be several demonstrations. Mr. Edwards of the Haslemere Museum will give continuous projection during the evening of living pond-life. A group of members will show the method of collecting, cleaning, etc., of Diatomaceæ. Methods of recording by means of drawing specimens and structures seen under the microscope will also be demonstrated. Dr. Gunther, of the Old Ashmolean, Oxford, will stage a demonstration of contributions by the late Mr.?.?. Nelson to microscopy. In addition to this, Dr. Gunther will give a demonstration of the original works of Hooke, showing proofs of the plates and the first editions of his book. It is hoped that the Royal Society, which owns a Hooke microscope, will exhibit it. Demonstrations are also expected from the British Museum (Natural History), King's College, Queen Mary College, etc. Cards of admission can be obtained from the Assistant Secretary, Miss Arnold, 58 Warwick Road, Ealing, W.5.