C0^' TENTS OF N° 291.— Fourth Series, 



X. On the Nature of Electricity. By M. E. Edlund page 81 



XI. Reply to some Remarks of the Hon. J. W. Strutt on Gaseous 

 Pressure. By Robert Moon, M,A., Honorary Fellow of Queen's 

 College, Cambridge 101 



XII. Researches in Actino-Chemistry. — Memoir First. On the 

 Distribution of Heat in the Spectrum. By John William Draper, 

 M.D., LL.D., President of the Faculties of Science and of Medicine 



in the University of New York. (With a Plate.) . 104 



XIII. A necessary Correction of one of Mr. Tait's Remarksc By 



R. Clausius .... 117 



XIV. The Atomic Theory, in Reply to Dr. Wright. By R. W. 

 Atkinson, F.C.S 118 



XV. Remarks on the alleged ambiguity, insufficiency, and unne- 

 cessariness of the Atomic Theory. By Alfred Tribe 121 



XVI. Earthlight on the Moon. By N. S. Shaler, Professor of 

 Palaeontology, Harvard University 123 



XVII. A Contribution to our knowledge of Atmospheric Waves. 



By W. R. BiRT, F.R.A.S., F.M.S 125 



XVIII. Notices respecting New Books: — British Rainfall, 1871. 



By G. J. Symons 138 



XIX. Proceedings of Learned Societies : — 



Royal Society : — Dr. J. H. Gladstone and Mr. A. Tribe on 

 the Action of Oxygen on Copper Nitrate in a state of Tension ; 

 The Astronomer Royal on a supposed Periodicity in the ele- 

 ments of Terrestrial Magnetism, with a period of 26^ days. 139--145 



Geological Society 146-149 



XX. Intelligence and Miscellaneous Articles : — 



Researches on the Electric Jet in Rarefied Gases, and in particular 

 on its Mechanical Force, by MM. A. de la Rive and E. Sar- 

 rasin 149 



On the Electrical Condition of Gas-flames, by John Trowbridge, 

 Assistant Professor of Physics 153 



On the Primary Spectrum of Iodine, by M. G. Salet ....,.,. 156 



On a simple Apparatus for the production of Ozone with Elec- 

 tricity of High Tension, by Professor Arthur W. Wright .... 156 



On a singular appearance of Magnesium in the Chromosphere of 

 the Sun, by M. Tacchini, in a letter addressed to M. Faye . . 159 



*^* It is requested that all Communications for this Work may be addressed, 

 post-paid, to the Care of Messrs. Taylor and Francis, Printing Office, Red 

 Lion Court, Fleet Street, London. 



