CONTENTS. 
Vll 
On the Decomposition of Forces externally applied to an Elastic Solid. 
By W. J. Macquorn Rankine, O.E., LL.D., F.R.SS. Lond. & Edin., 611 
On Geometric Mean Distance. By Professor Olerk Maxwell, . 613 
On a Singular Case of Rectification in Lines of the Fourth Order. By 
Edward Sang, Esq., . . . . , .613 
On the Wheeling of Birds. By Professor FIeeming Jenkin, . 615 
Notice of a New Family of the Echinodermata. By Professor Wyville 
Thomson, LL.D., F.R.SS. L. & E., F.L.S., F.G.S., . . 615 
On the Principles which regulate the Incidence of Taxes. By Pro¬ 
fessor Fleeming Jenkin, . . . . . .618 
Additional Notes on the Occurrence of the Sperm Whale in the Scot¬ 
tish Seas. By Professor Turner, . . . . .632 
Address on Thermo-Electricity. By Professor Tait, . . . 644 
Note on Cystine. By James Dewar, F.R.S.E., . . . 644 
Remarks on Contact-Electricity. By Sir William Thomson, . 648 
On the Curves of the Genital Passage as regulating the movements of 
the Foetus under the influence of the Resultant of the Forces of 
Parturition. By Dr J. Matthews Duncan, . . . 648 
On a Method of Determining the Explosive Power of Gaseous Com¬ 
binations. By James Dewar, Esq., .... 662 
Note on Sprengehs Mercurial Air-Pump. By James Dewar, Esq., . 662 
Exhibition of a large series of abnormal cones of Pinus Pinaster. 
By Professor Alexander Dickson, . . . . .663 
On the Connection between Chemical Constitution and Physiological 
Action— Continued. On the Physiological Action of the Salts of 
Trimethylsulphin. By Professor Crum Brown and Dr Thomas R. 
Fraser, ........ 663 
On the Mean Monthly Rainfall of Scotland. By Alexander Buchan, 665 
Note on the Strain Function, By Professor Tait, . . . 667 
On the Motion of Rigid Solids in a Liquid circulating Irrotationally 
through Perforations in them or in any Fixed Solid. By Sir Wil¬ 
liam Thomson, ....... 668 
On the Extraction of the Square Root of a Matrix of a Third Order. 
By Professor Cayley, . . . . . .675 
Second Note on the Strain Function. By Professor Tait, . . 682 
Note on the Rate of Cooling at High Temperatures. By Professor 
Tait, . . . . . . . .682 
Notice of a Large Boulder in the Parish of Rattray, and County of 
Perth, having on one of its sides Cups and Grooves, apparently 
artificial. By D. Milne Home, ..... 682 
On the Fruiting of the Ipecacuan Plant (Cephaelis Ipecacuanha, Rich.) 
in the Royal Botanic Garden. By Professor Balfour, . . 688 
On Cardiocarpon. By Professor Duns, D.D., F.R.S.E., New College, 692 
On the Composition of the Flesh of the Salmon in the “ Clean” and 
“ Foul” condition. By Sir Robert Christison, Bart., . . 694 
On Recent Estimates of Solar Temperature. By James Dewar, Esq., 697 
On the Temperature of the Electric Spark. By Janies Dewar, Esq., 699 
On the Action of Water on Lead. By Sir Robert Christison, Bart., . 699 
On the Preservation of Iron Ships. By James Young, Esq. of Kellie, 702 
First Report by the Committee on Boulders appointed by the Society, 703 
On the Chemical Efficiency of Sunlight. By James Dewar, Esq. . 751 
On the Rainfall of the Continents of the Globe. By Alexander 
Buchan, Secretary of the Scottish Meteorological Society, A.M., . 755 
On the Lunar Diurnal Variation of Magnetic Delineation at Trevan- 
drum, near the Magnetic Equator. By J. A. Broun, F.R.S., , 756 
