ix 



Page 



Contributions to the History of the Opium Alkaloids. — Part II. On he 

 Action of Hydrohromic Acid on Codeia and its derivatives. By C. R. A. 

 Wright, D.Sc, Lecturer on Chemistry in St. Mary's Hospital Medical 

 School 504 



On the Measurement of the Chemical Intensity of Total Daylight made at 

 Catania during the Total Eclipse of December 22, 1870. " By Henry E. 

 Roscoe, F.R.S., and T. E. Thorpe, F.R.S.E 511 



On the Calculation of Eider's Constant. By J. W. L. Glaisher, B. A., F.R.A.S. 514 



Records of the Magnetic Observations at the Kew Observatory. No. IV. — 

 Analysis of the principal Disturbances shown by the Horizontal and Ver- 

 tical Force Magnetometers of the Kew Observatory from 1859 to 1864. 

 By General Sir Edward Sabine, K.C.B., President 524 



Amended Rule for working out Sumner's Method of finding a Ship's Place. 

 By Professor Sir William Thomson, F.R.S 524 



On Linear Differential Equations.— No. V. By W. H. L. Russell, F.R.S. 526 



On the Undercurrent Theory of the Ocean, as propounded by recent ex- 

 plorers. By Captain Spratt, C.B., R.N., F.R.S 528 



On the Physical Principles concerned in the passage of Blood-corpuscles 

 through the Walls of the Vessels. By Richard Norris, M.D., Professor 

 of Physiology, Queen's College, Birmingham 556 



List of Presents 564 



Index 



573 



Obituary Notices of Fellows deceased : 



James David Forbes 



i 



Johann Evangelista Purkinje 



Sir James Clark 



ix 



William Allen Miller 

 J ohn Thomas Graves . 



xm 

 xix 

 xxvii 



