CONTENTS. 



MEMOIRS. page 



On a Magnetometer for showing the Influence of Temperature on the 

 Magnetization of Iron and other Magnetic Substances. By Henry 

 Wilde, F.R.S 2 



On the Affinities of Polybasic Acids. By Bevan Lean, D.Sc, B.A., 

 Assistant Lecturer, and late Bishop Berkeley Fellow of Owens 

 College. Communicated by W. H. Peekin, jun., F.R.S 19 



On the light thrown upon the question of the Growth and Development of 

 the Carboniferous Arborescent Lepidodendra by a study of the details 

 of their Organisation. By W. C. Williamson, LL.D. and F.R.S., 

 Emeritus Professor of Botany in the Owens College, Manchester ... 31 



On the Multiple Proportions of the Atomic Weights of Elementary 

 Substances in relation to the unit of Hydrogen. By Henry Wilde, 

 F.R.S 67 



On a Comparison of the Thermometers used by the late Dr. Joule with 

 the Standards of the Bureau International des Poids et Mesures. By 

 Arthur Schuster, F.R.S 87 



On the Evidence afforded by Bode's Law of a permanent Contraction of 

 the Radii Vectores of the Planetary Orbits. By Henry Wilde,F.R.S. 95 



On Kaloxyloti Hookeri, Will, and Lyginodendron Oldhamium, Will. By 

 Thomas Hick, B.A., B.Sc, A.L.S., Assistant Lecturer in Botany, 

 Owens College. Communicated by F. E. Weiss, B.Sc, Professor 

 of Botany at the Owens College ... ... ... ... ... ... 109 



A Sketch of the Limitations which are enforced upon the Mathematical 

 Forms of the Expressions for Physical Quantities in a Continuous 

 Medium in consequence of the necessity for their Permanence of Form. 

 By R. F. Gwyther, M.A 119 



On the True Resistance and on the Back Electromotive Force of the 

 Electric Arc. By Julius Frith, 1851 Exhibition Scholar, the 

 Owens College, Manchester. Communicated by Arthur Schuster, 

 F.R.S 139 



Note on Mr. Frith's paper " On the True Resistance and on the Back 

 Electromotive Force of the Electric Arc." By Arthur Schuster, 

 F.R.S 148 



On Some Remarkable Passages in the writings of Benjamin Franklin. 

 By Arthur Schuster, F.R.S ... 152 



