CONTENTS 
OF VOL. 151, 
I. The Bakeeian Lectuke. — On the Absorption and Radiation of Heat by Gases and 
Vapours^ and on the Physical Connexion of Radiation, Absorption, and Conduction. 
By John Tyndall, Esp, F.R.S., Member of the Academies and Societies of Hol- 
land, Genera, Gottingen, Zurich, Halle, Marburg, Breslau, la Societe Philoma- 
thigue of Paris, &c. ; Professor of Natural Philosophy in the Royal Institution, 
and in the Government School of Mines P^-ge 1 
II. On an Extension 0/ Akbogast’s Method of Derivations. By Aethue Cayley, Esq., 
F.R.S. 37 
III. On the Equation for the Product of the Differences of all but one of the Roots of a 
given Equation. By Aethue Cayley, Esq., F.R.S 45 
IV. On the Synthesis of Succinic and Pyrotartaric Acids. By Maxwell Simpson, M.B. 
Communicated by Dr. Feankland, F.R.S. 61 
V. On the Calculus of Symbols, with Applications to the Theory of Differential Equations. 
By W. H. L. Kussell, Esq., A.B. Communicated by Aethue Cayley, Esq., 
F.R.S. 
VI. On the Properties of Inquid Carbonic Acid. By G. Goee, Esq. Communicated by 
Professor Tyndall, F.R.S. 83 
VII. On Magnetic Storms and Earth-Currents. By Chaeles V. Walkee, Esq., F.R.S., 
F.R.A.S. 
VIII. On the Surface-condensation of Steam, By J. P. Joule, LL.D., f.R.S., Pre- 
sident of the Inter ary and Philosophical Society of Manchester, Ac. , . . 133 
IX. On the Effect produced on the Deviations of the Compass by the Length and Arrange- 
ment of the Compass - Needles ; and on a New Mode of correcting the Quadrantal 
