CONTENTS. 
PART I. 
I. On the Determination of V erdet’s Constant in Absolute Units. By J. E. El. Gordon, 
B.A., Gonville and Cains College, Cambridge. — 1st and ‘Did Memoirs. Commu- 
nicated by J. Clerk Maxwell, F.B.S page 1 
II. The Calculus of Chemical Operations; being a Method for the Investigation, by 
means of Symbols, of the Laws of the Distribution of Weight in Chemical Change. 
— Part II. On the Analysis of Chemical Events. By Sir B. C. Brodie, Bart., 
F.B.S. , late Professor of Chemistry in the University of Oxford . . . . 35 
III. On the Structure of a Species of Millepora occurring at Tahiti , Society Islands. 
By H. N. Moseley, Fellow of Fxeter College, Oxford, Naturalist to the 
‘ Challenger ’ Expedition. Communicated by Professor Sir C. Wyville Thomson, 
F.B.S., Director of the Civilian Scientific Staff 117 
IV. A Contribution to Terrestrial Magnetism; being the Becord of Observations of 
the Magnetic Inclination, or Dip, made during the Voyage of II. M.S. 1 Iron Duke ' 
to China and Japan, &c., 1871-75. By Vice-Admiral Sir Charles Shadwell, 
K.C.B., F.B.S. 137 
V. Further Besearches on the Deportment and Vital Persistence of Putrefactive and 
Infective Organisms from a Physical point of View. By John Tyndall, D.C.L., 
LL.D., F.B.S. 149 
VI. On the Absorption-Spectra of Bromine and of Iodine Monochloride. By H. E. 
Boscoe, F.B.S., and T. E, Thorpe, F.B.S 207 
VII. On the Organization of the Fossil Plants of the Coal-measures . — Part VIII. 
Ferns (continued) and Gymnospermous Stems and Seeds. ByW. C. Williamson, 
F.B.S., Professor of Natural History in the Owens College, Manchester . 213 
VIII. On the Influence of Geological Changes on the Earth's Axis of Potation. By 
George H. Darwin, M.A., Fellow of Trinity College, Cambridge. Communicated 
by Professor J. C. Adams, F.B.S. 271 
IX. The Action of Light on Selenium. By Professor W. G. Adams, M.A . , F.B.S., 
and R. E. Day, M.A 313 
