CONTENTS. 
VIII. On the Gas Voltaic Battery. — Experiments made with a view of ascertaining the 
rationale of its action and its application to Eudiometry. By W. R. Grove, 
Esq., M.A . , F.B.S., Prof Exp. Phil., London Institution .... page 91 
IX. Contributions to Terrestrial Magnetism. — No. IV. By Lieut. -Colonel Edward 
Sabine, R.A , F.R.S, 113 
X. Contributions to 'Terrestrial Magnetism. — No. V. By Lieut. -Colonel Edward 
Sabine, R.A., F.R.S 145 
XI. On the Organ of Hearing in Crustacea. By Arthur Farre, M.D., F.R.S. 233 
XII. On the Structure, Relations, and Development of the Nervous and Circulatory 
Systems, and on the Existence of a Complete Circulation of the Blood in 
Vessels, in Myriapoda and Macrourous Arachnida. — First Series. By George 
Newport, Esq., President of the Entomological Society of London, Member of the 
Royal College of Surgeons, and Corresponding Member' of the Philomathic 
Society of Paris. Communicated by P. M. Roget, M.D., Sec. R.S., 8$c. . 243 
XIII. T he Bakerian Lecture. — An Account of several new Instruments and Processes 
for determining the Constants of a Voltaic Circuit. By Charles Wheatstone, 
Esq., F.R.S., Professor of Experimental Philosophy in King’s College, London, 
Corresponding Member of the Academy of Sciences at Paris, &$c. . . . 303 
XIV. On the Respiration of the Leaves of Plants. By William Hasledine Pepys, 
Esq., F.R.S 329 
Index 333 
Appendix. 
Meteorological Journal kept at the Apartments of the Royal Society, by order of the 
President and Council. 
