Contents. 
V 
PAGE 
Note on a New Fossil Foot-Print from the Permian Sandstone of 
Dumfriesshire. By Patrick Dudgeon, F.R.S.E. (Plate I.), . 154 
On the Decennial Period in the Mean Amplitude of the Diurnal 
Oscillation and Disturbance of the Magnetic Needle and of the 
Sun-spot Area. By J. A. Broun, F.R.S., . . . .155 
On the Parallel Roads of Lochaber. By David Milne Home, LL.D., 159 
Physical Observations in Northern Asia. By Professor G. Forbes, . 161 
On Parallel Motions. By the Rev. John Wilson, M.A., Bannock- 
burn Academy. Communicated by Professor Kelland, . .161 
Laboratory Notes. By Professor Tait — 
a. On the Passage of the Electric Current from Amalgamated 
Zinc Sulphate Solution. By J. G. MacGregor, M.A., . 170 
b. On the Thermo-Electric Properties of Cobalt, &c. By 
Messrs Knott, MacGregor, and C. M. Smith, . .170 
c. Measurements of the Potentials required for Long Sparks 
of a Holtz Machine. By Messrs Macfarlane and Paton, 170 
Note on Orthogonal Isothermal Surfaces. By Professor Tait, . 170 
Notice of some Recent Atmospheric Phenomena. By Professor Tait, 170 
Report by the Society’s Boulder Committee. (Plates II. and III.), 170 
Election of Office-Bearers, ...... 203 
Opening Address by the Rev. W. Lindsay Alexander, D.D., . . 204 
On the Roots of the Equation V ptpp = 0. By Gustav Plarr. Com- 
municated by Professor Tait, ..... 237 
Applications of the Theorem that Two Closed Plane Curves intersect 
an even number of times. By Professor Tait, . . . 237 
On the Distribution of Volcanic Debris over the Floor of the Ocean, 
— its Character, Source, and some of the Products of its Disintegra- 
tion and Decomposition. By J ohn Murray, Esq. Communicated 
by Sir C. Wyville Thomson, ..... 247 
On New and Little-known Fossil Fishes from the Edinburgh Dis- 
trict. No. I. By R. H. Traquair, M.D., F.G.S., . . . 262 
On the Ruff ( Machetes Pugnax). By Professor Duns, . . 272 
Communication from the President relative to the Administration 
of the Government Fund of £4000, . . . .275 
On New and Little-known Fossil Fishes from the Edinburgh Dis- 
trict. No. II. By R. H. Traquair, M.D., F.G.S., . . 275 
Note on Clapeyron’s Formula. By Professor Dewar, . . 283 
Note on the Specific Gravity of Ocean Water. By J. Y. Buchanan, 283 
Note on the Manganese Nodules found on the bed of the Ocean. 
By J. Y. Buchanan, ...... 287 
Note on the Measure of Beknottedness. By Professor Tait, . . 289 
Note on the Effect of Heat on Infusible Impalpable Powders. By 
Professor Tait, . . . . . . .298 
Abstract of Additional Memoir on the Parallel Roads of Lochaber. 
By D. Milne Home, LL.D., ..... 299 
