11 
PAGE 
On the Operator <p'y). By Professor Tait, . . 607 
Note on Pendulum Motion. By Professor Tait, . . 608 
On the Decomposition of Forces externally applied to an 
Elastic Solid. By W. J. Macquorn Bankine, C.E., 
LL.D., E.B.SS. Bond, and Edin., . . . 611 
On G-eometric Mean Distance. By Professor Clerk- 
Maxwell, ...... 613 
On a Singular Case of Bectification in Lines of the Fourth 
Order. By Edward Sang, Esq., . . .613 
Monday, 29 th January 1872. 
On the Wheeling of Birds. By Professor Fleeming 
Jenkin, . . . . . 615 
Notice of a New Family of the Echinodermata. By Prof. 
Wyville Thomson, LL.D., F.B.SS.L. and E., F\L.S., 
F.G.S., ...... 615 
On the Principles which Begulate the Incidence of Taxes. 
By Professor Fleeming Jenkin, . . . 618 
Additional Notes on the Occurrence of the Sperm Whale 
in the Scottish Seas. By Professor Turner, . . 632 
Monday , 5th February 1872. 
Address on Thermo-Electricity. By Professor Tait, . 644 
Note on Cystine. By James Dewar, F.B.S.E., . . 644 
Monday , 19 th February 1872. 
Bemarks on Contact-Electricitju By Sir William Thomson, 648 
On the Curves of the Genital Passage as regulating the 
o o o 
movements of the Foetus under the influence of the 
Besultant of the Forces of Parturition. By Dr J. 
Matthews Duncan, ..... 648 
On a Method of Determining the Explosive Power of Gase¬ 
ous Combinations. By James Dewar, Esq., . . 662 
Note on Sprengel’s Mercurial Air-Pump. By James 
Dewar, Esq., ...... 662 
Exhibition of a large series of Abnormal Cones of Pinus 
Pinaster. By Professor Alexander Dickson, . . 663 
For continuation of Contents , see pjp. 3 and 4 of Cover. 
