Contents. 
vii 
PAGE 
iSTote on a large Crystal of Calc-spar found in Lough Corrib by Pro- 
fessor Tait. By M. I’Abhe Ecnard, .... 530 
On Kadiation. By Professor Tait, . . . . .531 
On the Need for Decimal Subdivisions in Astronomy and Naviga- 
tion, and on Tables requisite therefor. By Edward Sang, LL.D., 533 
An Electro-Magnetic Declinometer. By A. Tanakadate, Assistant to 
the Professor of Physics in the University of Tokio, Japan. Coni- 
'municated by Prof. J. A. Ewing, University College, Dundee, . 544 
On an Equation in Quaternion Differences. By Professor Tait, . 561 
On Vortex Motion. By Professor Tait, .... 562 
Award of the Keith, Makdougall-Brisbane, and Neill Prizes, . 562 
On Efficiency of Clothing for maintaining Temperature. By Sir W. 
Thomson, 568 
On the Law of Inertia ; the Principle of Chronometry ; and the 
Principle of Absolute Clinural Rest, and of Absolute Rotation. 
By Professor James Thomson, LL.D., D.Sc., C.E., . . 568 
On a Modification of Gauss’s Method for determining the Hori- 
zontal Component of Terrestrial Magnetic Force, and the Magnetic 
Moments of Bar Magnets, in Absolute Measure. By Sir William 
Thomson, ........ 578 
On the Phenomenon of “ Greatest Middle” in the Cycle of a Class of 
Periodic Continued Fractions. By Thomas Muir, M.A., F.R.S.E., 578 
The Old Red Sandstone Volcanic Rocks of Shetland. By Messrs 
B. N. Peach and John Horne, of the Geological Survey of Scotland, 593 
On the Principles of Economics. Part I., Mathematical. Part II., 
Physical. By Mr P. Geddes, ..... 593 
An Integrating Hygrometer. By Professor C. Michie Smith, . 593 
On the Philosophy of Language. By Emeritus Professor Blackie, . 594 
On the Principles of Economics. Part III., Biological and Psycho- 
logical. By Mr P. Geddes, ..... 594 
Note on a New Form of Galvanometer. By Prof. James Blyth, . 594 
On Galvanic Currents passing through a very Thin Stratum of an 
Electrolyte. By Professor H. von Helmholtz, . . . 596 
On Cosmic Dust. By M. I’Abb^ Renard, .... 599 
Esempio del metodo di dedurre una superficie da una figura piana, 
dal Professore Luigi Cremona, . . . . .599 
On the Construction of the Canon of Logarithmic Sines. By Edward 
Sang, LL.D., . ...... 601 
On Stichocotyle nephropis, a new Trematode. By Mr J. T. Cunning- 
ham, B.A. Communicated by Mr John Murray, . . .619 
Scottish Vital Statistics. By Mr George Seton, Advocate, M.A. 
Oxon., ........ 619 
Experiments on the Chief Disinfectants of Commerce, with a view of 
ascertaining their Power of Destroying the Spores of the Anthrax 
bacillus. By A. Winter Blyth, Medical Officer of Health and 
Public Analyist. Communicated by Professor Turner, . . 633 
Sur la Reduction des Integrates Hyperelliptiques, extrait d’une 
lettre adressee a M. le Professeur Chrystal, par M. Hermite, . 642 
