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On certain Points in the Anatomy of Chiton. By Adam Sedgwick, 



M.A., Fellow of Trinity College, Cambridge , 121 



The Action of Cutting Tools. By A. Mallock 127 



On Seismic Experiments. By John Milne, F.G.S., and Thomas Gray, 



B.Sc, F.E.S.E 139 



On the Electrolytic Diffusion of Liquids. By G. Gore, LL.D., F.E.S 140 



On the Coefficients of Contraction and Expansion by Heat of the Iodide 

 of Silver, Agl, the Iodide of Copper, Cu 2 I 2 , and of Five Alloys of 

 these Iodides. By G. F. Eodwell, F.B.A.S., F.C.S., Science Master in 



Marlborough College 143 



On the Vibrations of a Vortex Ring, and the Action of Two Vortex 

 Eings upon each other. By J. J. Thomson, B.A., Fellow of Trinity 

 College, Cambridge 145 



Letter addressed to the Secretary E.S. by Dr. W. Eoberts, F.E.S 147 



December 15, 1881. 



On the Electromotive Properties of the Leaf of Dionsea in the Excited and 

 Unexcited States. By J. Burdon Sanderson, M.D., F.E.S., &c 148 



On some Effects of Transmitting Electric Currents through Magnetised 

 Electrolytes. By Dr. G. Gore, F.E.S 151 



Preliminary Eeport to the Solar Physics Committee on the Sun-spot 

 Observations made at Kensington. By J. N. Lockyer 154 



On /3-Lutidine. By C. Greville Williams, F.E.S 159 



On the Effect of the Spectrum on the Haloid Salts of Silver, and on 

 Mixtures of the same. By Captain Abney, E.E., F.E.S 164 



On a New Electrical Storage Battery. By Henry Sutton (Ballarat, 

 Victoria) 187 



December 22, 1881. 



On the Germinal Layers and Early Development of the Mole. By 

 Walter Heape 190 



On the Ehythm of the Heart of the Frog, and on the Nature of the 

 Action of the Vagus Nerve. By W. H. Gaskell, M.D. Cantab 199 



On Melting Point. By Edmund J. Mills, D.Sc, F.E.S., Young Professor 

 of Technical Chemistry in Anderson's College, Glasgow.... 203 



Memoir on the Theta-Functions, particularly those of Two Variables. 

 By A. E. Forsyth, B.A., Fellow of Trinity College, Cambridge 206 



On certain Geometrical Theorems. No. 1. By W. H. L. Eussell, F.E.S. 211 



On a Class of Invariants. By John C. Malet, M.A., Professor of Mathe- 

 matics, Queen's College, Cork 215 



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