THE COUNCIL OF THE ROYAL SOCIETY OF EDINBURGH JANUARY 1897. PRESIDENT. THE RIGHT HON. LORD KELVIN, G.C.V., LL.D., D.C.L., F.R.S., Grand Officer of the Legion of Honour of France, Member of the Prussian Order Pour le Merite, Foreign Associate of the Institute of France, Regius Professor of Natural Philosophy in the University of Glasgow. HONORARY VICE-PRESIDENTS, HAVING FILLED THE OFFICE OF PRESIDENT. His GRACE THE DUKE OP AEGYLL, E.G., K.T., D.C.L. Oxon., LL.D., FR.S FGS SIR DOUGLAS MACLAGAN, M.D., F.R.C.P.E., LL.D., Emeritus Professor of Medicai Jurisprudence in the University of Edinburgh. VICE-P RESIDE NTS. JAMES GEIKIE, LL.D., D.C.L., F.RS., Professor of Geology in the University of Edinburgh. THE HON. LORD M'LAREN, LL.D. Edin. and Glas., F.E.A.S., one of the Senators of the College of Justice. THE REV. PROFESSOR FLINT, D.D., Corresponding Member of the Institute of France. JOHN G. M'KENDRICK, M.D., F.R.C.P.E., LL.D., F.RS., Professor of Physiology in the University of Glasgow. GEORGE CHRYSTAL, M.A., LL.D., Professor of Mathematics in the University of Edinburgh. SIR ARTHUR MITCHELL, K.C.B., M.A., M.D., F.R.C.P.E., LL.D. GENERAL SECRETARY. P. GUTHRIE TAIT, M. A, D.Sc, Professor of Natural Philosophy in the University of Edinburgh. SECRETARIES TO ORDINARY MEETINGS. ALEXANDER CRUM BROWN, M.D., D.Sc, F.R.C.P.E., LL.D., F.RS., Professor of Chemistry in the University of Edinburgh. JOHN MURRAY, D.Sc, LL.D., Ph.D., F.RS., Director of the Challenger Expedition Publications. TREASURER. PHILIP R. D. MACLAGAN, F.F.A. CURATOR,OF LIBRARY AND MUSEUM. ALEXANDER BUCHAN, M.A., LL.D., Secretary to the Scottish Meteorological Society. COUNCILLORS. THOMAS R FRASER, M.D.,F.RC.P.E., LL.D., JAMES BURGESS, C.I.E., LL.D., M.R.A.S. F.R.S., Professor of Materia Medica in the JOHN STURGEON MACKAY, M.A., LL.D., University of Edinburgh. Mathematical Master in the Edinburgh ROBERT MUNRO, M.A., M.D. Academy. D. NOEL PATON, B.Sc, M.D., F.RC.P.E. RALPH COPELAND, Ph.D., Astronomer-Royal CARGILL G. KNOTT, D.Sc, Lecturer on Ap- for Scotland, and Professor of Practical plied Mathematics in the University of Astronomy in the University of Edinburgh. Edinburgh. DARCY W. THOMPSON, B.A, F.L.S., Pro- SIR WILLIAM TURNER, M.B., F.RC.S.E, fessor of Natural History in University LL.D., D.C.L., D.Sc. Dub., F.RS., Pro- College, Dundee. fessor of Anatomy in the University of THE REV. PROFESSOR DUNS, D.D. Edinburgh. LIEUT.-COL. FREDERICK BAILEY (late) R.E., SIR STAIR AGNEW, K.C.B., M.A., Registrar- Lecturer on Forestry in the University of General for Scotland. Edinburgh. VOL. XXXVIII. PART IV, 6 B.