Contents. 
vii 
PAGE 
Additional Note on Minding’s Theorem. By Professor Tait, . 407 
Private Business — Alteration of Law XVII., and Addition to Law 
XV. — Letter from the Society to Dr Balfour on his resigning the 
office of General Secretary, and Dr Balfour’s Letter in reply, . 408 
On the Distribution of Temperature under the Ice in Frozen Lakes. 
By J ohn Aitken, ....... 409 
Remarks on the Aborigines of the Andaman Islands. By Surgeon 
E. S. Brander, M.B., C.M., H.M. Bengal Medical Staff, Second 
Medical officer, Port Plair and Nicobars, Plate XV., . .415 
The Action of Sulphide of Potassium upon Chloroform. By W. W. 
J. Nicol, M.A. Communicated by Professor Crum Brown, . 425 
Note on the Elimination of Linear and Vector Functions. By Pro- 
fessor Tait, ........ 425 
On the Geology of the Rocky Mountains. By Professor Geikie, . 426 
On Comets. By Professor Forbes, ..... 426 
Note on the Velocity of Gaseous Particles at the Negative Pole of a 
Vacuum Tube. By Professor Tait, .... 430 
On Steam-pressure Thermometers of Sulphurous Acid, Water, and 
Mercury. By Sir W. Thomson, • . . . . 432 
On a Sulphurous Acid Cryophorus. By Sir W. Thomson, . . 442 
Vibrations of a Columnar Vortex. By Sir William Thomson, . 443 
The Structure of the Comb-like Branchial Appendages and the 
Teeth of the Basking Shark ( Selache maxima). By Professor 
Turner, M.B., F.R.S., . . . . . . 457 
Preliminary Report on the Tunicata of the “Challenger” Expedition. 
By W. A. Herdman, B.Sc., Baxter Scholar in Natural Science in 
the University of Edinburgh, . . . . . 458 
On some Applications of Rotatory Polarization. By Professor Tait, 473 
The Topography of Jerusalem. By Lieut. Claude Reignier Conder, 
R.E., . . . . . . . .474 
The Geology of the Faroe Islands. By James Geikie, LL.D., 
F. R.SS.L. & E., 495 
Meteorological Note by Mr Alexander Wallace. Communicated by 
Professor Piazzi Smyth, ...... 500 
On the Colouring of Maps. By Professor Tait, . . . 501 
On the Structure and Origin of Coral Reefs and Islands. By John 
Murray, . . . . . . . .505 
Rock-Weathering, as illustrated in Edinburgh Churchyards. By 
Professor Geikie, Plate XIV., . . . . . 518 
On a Realised Sulphurous Acid Steam- Pressure Thermometer, and 
on a Sulphurous Acid Steam-Pressure Differential Thermometer. 
By Sir William Thomson, ...... 532 
On a Differential Thermoscope founded on Change of Viscosity of 
Water with Change of Temperature. By Sir William Thomson, . 537 
On a Thermomagnetic Thermoscope. By Sir William Thomson, . 538 
O11 a Constant Pressure Gas Thermometer. By Sir W. Thomson, . 539 
On the Occultation of the Star 103 Tauri. (b. a. c. 1572.) By 
Edward Sang, ....... 546 
