IV 
PAGE 
On the Curve of Second Sines and its Variations. By 
Edward Sang, Esq., . . . . 356 
Laboratory Notes. By Professor Tait — 
On the Thermo-electric Positions of Sodium and 
Potassium, . . . . 362 
On a New Form of Mariner’s Compass. By Sir William 
Thomson, ...... 363 
Monday , 6 th April 1874. 
Further Note on Spectra under exceedingly Small Pressures. 
By Professor Tait and James Dewar, Esq., . . 363 
On the After-Glow of Cooling Iron at a Dull-red Heat. 
By George Forbes, Esq , 363 
On a Form of Radiation Diagram. By G-eorge Forbes, 
Esq., . ... . . . 366 
On the Semicircular Canals of the Internal Ear. By Pro- 
fessor Crum Brown, . . . . 370 
Monday, 20 th April 1874. 
On Last-Place Errors in Vlacq’s Table of Logarithms. By 
Edward Sang, Esq., ..... 371 
Note on the Submerged Fossil Trees of Granton Quarry. 
By Sir Robert Christison, Bart., Hon. V.P., R.S.E., . 377 
Note on Grouse Disease. By Professor Maclagan, , 378 
Latent Heat of Mercury Vapour. By James Dewar, Esq., 380 
Notes by James Dewar, Esq. — 
(1.) Problems of Dissociation; (2.) Formation of 
Allotropic Sulphur ; (3.) Heat of Fermentation, . 380 
Further Note on Continuants. By Thomas Muir, M.A., 
F.R.S.E., Assistant to the Professor of Mathematics in 
Glasgow University, ..... 380 
Monday , 4 th May 1874. 
On the Formation of Allotropic Sulphur. By James Dewar, 
Esq., .382 
On Some Compounds of Dimethyl-Thetine. By Professor 
Crum Brown and Dr E. A. Letts, . . . 382 
On a New Example of the Opheliidae ( Linotrypane apogon) 
from Shetland. By W. C. MTntosh, M.D., . .'4 386 
Concluding Remarks by David Milne Home, LL.D., . 390 
