Page 



The Diffusion of Ions into Gases. By John S. Townsend, M.A. 

 (Dublin), Clerk Maxwell Student, Cavendish Laboratory, Cambridge. 

 Communicated by Professor J. J. Thomson, F.R.S 192 



On the Presence of Oxygen in the Atmospheres of certain Fixed Stars. 

 By David Gill, C.B., F.R.S., &c, Her Majesty's Astronomer at the 

 Cape of Good Hope. (Plate 8) 196 



No. 417. 



Annual Meeting for the Election of Fellows 206 



Meeting of June 1, 1899, and List of Papers read 207 



The Characteristic of Nerve. By Augustus D. Waller, M.D., F.R.S 207 



The Parent-rock of the Diamond in South Africa. By T. G. Bonnev, 

 D.Sc, LL.D., V.P.R.S 223 



Photographic Researches on Phosphorescent Spectra : on Victorium, a 

 new Element associated with Yttrium. By Sir William Crookes, 

 F.R.S. (Plate 9) '. 237 



Experimental Contributions to the Theory of Heredity. A. Telegony. 

 By J. C. Ewart, M.D., F.R.S., University of Edinburgh 243 



No. 418. 



Meeting of June 8, 1899 (Discussion Meeting) 252 



On Preventive Inoculation. By W. M. Haffkine, CLE. Communi- 

 cated by Lord Lister, P.R.S 252 



Meeting of June 15, 1899, and List of Papers read 272 



A Preliminary Note on the Morphology and Distribution of the 

 Organism found in the Tsetse Fly Disease. By H. G. Plimmer and 

 J. Rose Bradford, F.R.S., Professor Superintendent of the Brown 

 Institution 274 



No. 419. 



The Colour Sensations in Terms of Luminosity. By Captain W. de W. 



282 



Abney, C.B., D.C.L., F.R.S. 



The Conductivity of Heat Insulators. By C. G. Lamb, M.A., B.Sc, 

 and W. G. Wilson, B.A. Communicated by Professor Ewing, 

 F.R.S 283 



On the Orientation of Greek Temples, being the Results of some 

 Observations taken in Greece and Sicily, in May, 1898. By F. C. 

 Penrose, M.A., F.R.S =••<• 288 



On the Comparative Efficiency as Condensation Nuclei of positively 

 I and negatively charged Ions. By G. T. R. Wilson, M.A. Communi- 

 cated by the Meteorological Council 289 



