VI 



Page 



Researches into the Colouring Matters of Human Urine, with an Account 

 of the Separation of Urobilin. By C. A. MacMunn, B.A., M.D 250 



On the Coalescence of Amoeboid Cells into Plasmodia, and on the so-called 

 Coagulation of Invertebrate Fluids. By P. Geddes. (Plate 5) 252 



On the Analytical Expressions which give the History of a Fluid Planet 

 of small Viscosity, attended by a Single Satellite. By G. H. Darwin, 

 F.RS 255 



On the Modifications of the Spectrum of Potassium which are effected 

 by the Presence of ^Phosphoric Acid, and on the Inorganic Bases and 

 Salts which are found in combination with Educts of the Brain. By 

 J. L. W. Thudichum, M.D., F.R.C.P.L 278 



On Magnetic Circuits in Dynamo- and Magneto-Electric Machines. 

 No. 2. By Lord Elphinstone and Charles W. Vincent, F.R.S.E., 

 F.C.S., F.I.C 287 



Some further Observations on the Influence of Electric Light upon Vege- 

 tation. By C. William Siemens, D.C.L., LL.D., F.RS 293 



List of Presents 295 



No. 203.— April 8, 1880. 



Note on Thermal Transpiration. By O. Reynolds, F.R.S., Professor of 

 Engineering in Owens College, Manchester. In a letter to Professor 

 Stokes, Sec. RS 300 



On the Sensitive State of Vacuum Discharges. Part II. By William 

 Spottiswoode, D.C.L., LL.D., Pres. RS., and J. Fletcher' Moulton, 

 M.A., late Fellow of Christ's College, Cambridge 302 



April 15, 1880. 



Description of some Remains of the Gigantic Land-lizard {Megalarda 

 prisca, Owen) from Australia. Part II. By Professor Owen, C.B., 

 F.R.S 304 



On an Electro-Magnetic Gyroscope. By M. Wilfrid de Fonvielle . 305 



Report on the Exploration of the Caves of Borneo. By A. Hart Everett. 

 Introductory Remarks. By John Evans, D.C.L., LL.D., Treas. RS. ; 

 and Note on the Bones collected. By G. Busk, V.P.R.S 310 



April 22, 1880. 



Effects of Electric Currents on the Surfaces of Mutual Contact of Aqueous 

 Solutions. By G. Gore, LL.D., F.R.S 322 



On the Critical State of Gases, By William Ramsay, Ph.D., Professor of 

 Chemistry in University College, Bristol 323 



Reversion of the Atomic Weight of Aluminium. By J. W. Mallet, F.R.S., 

 Professor of Chemistry in the University of Virginia 329 



