CONTENTS OF VOL. XXI.-~-FOURTH SERIES. 
Old Red Sandstone in the Counties of Forfar and Kin- 
cardine, Scotland ..... 
The Rev. P. B. Brodie on the Distribution of the Corals in 
MORAY e 35 die ie Od ho Ab VISIR Baers 
The Rev. W. 8. Symonds on the Sections of the Malvern 
and Ledbury Tunnels, on the Worcester and Hereford 
Railway . : 
On the Fibrous Arrangement of Iron and Glass T ubes, by Dr. 
EE ehh if wn ed sod se ye na 00 «8 
On the Calcium Spectrum, by F. W. and A. Dupré ........ 
On the Lunar Tables and the Inequalities of Long Period due to 
the Action of Venus, by M. de Pontécoulant .......... i's 
NUMBER CXL.—APRIL. 
Prof. Kirchhoff on a New Proposition in the Theory of Heat. . 
Mr. J. Croll’s Remarks on Ampére’s Experiment on the Repul- 
sion of a Rectilinear Electrical Current on itself.......... 
Prof. Challis on ‘Theories of Magnetism and other Forces, in 
reply to Remarks by Professor Maxwell . a 
Mr. ‘I. Tate on certain peculiar Forms of Capillary Action fe 
Mr, A. Cayley on a Theorem of Abel’s relating to Equations of 
SM OFCEE OVP ne. ae UP ebb ck Chee dak 
Mr. D. Vaughan on ‘the Stability of Satellites in small Orbits, 
and the Theory of Saturn’s Rings .... 
Mr. J. S. Stuart Glennie on the ‘Principles of Energetics. — 
Part I. Ordinary Mechanics..... : 
Prof. Maxwell on Physical Lines of Force. (With ¢ a Plate. ie : 
Dr. Atkinson’s Chemical Notices from Foreign Journals...... 
Mr. W. Crookes on the existence of a new ‘Element, probably 
Mere SDM GROUP We )h fei. eds Mae eek 
Proceedings of the Geological Society :-— 
Mr. J. D.Smithe on the Gravel and Boulders of the Punjab. ¢ 3 
Prot lauxiey on Pieraspis Dunensis. 0... eee ee eck ss 
Mr. W. Whitaker on the ‘ Chalk-rock’ lying between the 
Lower and the Upper Chalk in Wilts, Berks, Oxon, 
Pee OMOGELCUUS es ee ee soe hss eed ele ielae « 
Sir R. I. Murchison and Mr. A. Geikie on the Altered 
Rocks of the Western and Central Highlands, and on 
the Coincidence between Stratification and Foliation in 
the Crystalline Rocks of the Highlands ............. 
Prof. Harkness on the Rocks of portions of the Highlands 
of Scotland. . 
Mr. F. Drew on ‘the Succession’ of Beds in the Hastings 
Sand in the Northern portion of the Wealden Area. . 
Mr. J. W. Kirkby on the Permian Rocks of the South of 
Yorkshire ...... esos 
On some Results in Electro-magnetism ‘obtained “with the 
Balance Galvanometer, by George Blan, WEA. GERK LED. GS 
306 
306 
308 
309 
310 
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