PROCEEDINGS OF 

 THE ROYAL SOCIETY. 



VOL. LXI. NO. 377. 



CONTENTS. 



PAGE 



On the Action exerted by certain Metals and other Substances on a Photo- 

 graphic Plate. By W. J. Russell, Ph.D., F.R.S., Lecturer on Chemistry 

 at St. Bartholomew's Hospital ......... 424 



On the relative Behaviour of the H and K lines of the Spectrum of Calcium. 



By William Huggins, D.C.L., LL.D., F.R.S., and Mrs. Huggins . 433 



Further Observations of Enhanced Lines. By J. Norman Lockyer, C.B., 



F.RS. . . . . . 441 



The Total Solar Eclipse of August 9, 1896. Report on the Expedition to Kio 



Island. By J. Norman Lockter, C.B., F.R.S 444 



On the Classification of Stars of the d Cephei Class. By J. Norman Loceyer, 

 C.B., F.R.S . . ' . 445 



On Lunar and Solar Periodicities of Earthquakes. By Arthur Schuster, 



F.R.S. 455 



The Vector properties of Alternating Currents and other Periodic Quantities. 



By W. E. Sumpnes, D.Sc. Communicated by O. Henrici, F.R.S. . 465 



Note on recent Investigations on the Mechanical Equivalent of Heat. By 



E. H. Griffiths, F.R.S 479 



Cathode Rays and some analogous Rays. By Silvanus P. Thompson, D.Se., 



F. RS 481 



Electrification of Air, of Vapour of Water, and of other Gases. By Lord 

 Kelvin, G.C.V.O., F.R.S., Magnus Maclean, D.Sc, F.R.S.E., and 

 Alexander Galt, B.Sc, F.R.S.E 483 



On the Change of Absorption produced by Fluorescence. By John Burke, 

 B.A. (Dub.), Berkeley Fellow of the Owens College, Manchester. Com- 

 municated by Professor Arthur Schuster, F.R.S 485 



For continuation of Contents see 2nd page of Wrapper. 



Price Three Shillings. 



August 20, 1897. 



