CONTENTS OF VOL. XXXIII. FOURTH SERIES. Vll 



Page 



M. J.-M. Gaugain on Grove's Gas-Battery 465 



Notices respecting New Books : — The Rev. John Kerr's Ele- 

 mentary Treatise on Rational Mechanics 468 



Proceedings of the Royal Society : — 



Mr. C. W. Siemens on the Conversion of Dynamical into 

 Electrical Force without the aid of Permanent Mag- 

 netism 469 



Mr. C. Wheatstone on the Augmentation of the Power of 

 a Magnet by the reaction thereon of Currents induced 



by the Magnet itself 471 



Mr. J. Clerk Maxwell on the Theory of the Maintenance 

 of Electric Currents by Mechanical Work without the 



use of Permanent Magnets 474 



On the Disengagement of Gases from their saturated Solutions, 



by M. Gernez 479 



Induction Experiments, by M. L. Daniel 481 



Transport of a Body by the Voltaic Current and by Induction- 

 currents, by M. Daniel 482 



NUMBER CCXXVI.— SUPPLEMENT. 



Prof. Helmholtz on Integrals of the Hydrodynamical Equations, 



w r hich express Vortex-motion 485 



Prof. A. de la Rive on the Action of Magnetism upon the Elec- 

 tric Discharge in highly Rarefied Gaseous Media 512 



Mr. S. Roberts on the Order of the Conditions that an Alge- 

 braical Equation may have a set of Multiple Roots 530 



Mr. J. C. Moore on Mr. Croll's Paper on the Influence of the 



Obliquity of the Ecliptic on Climate 536 



Hon. Chief Justice Cockle on the Conversion of Integrals .... 537 

 Prof. Rood on a Theory proposed by Fresnel, and on a mode of 



measuring the average size of very fine Particles 540 



Proceedings of the Royal Society : — 



Mr. C. F. Varley on certain Points in the Theory of the 

 Magneto-electric Machines of Wilde, Wheatstone, and 



Siemens 543 



Mr. W. Ladd on a Magneto-electric Machine 544 



Mr. F. A. Abel on the Stability of Gun-cotton 545 



Mr. A.Claudet on a new fact relating to Binocular Vision. 549 

 Proceedings of the Geological Society: — 



Mr. W. B. Dawkins on Bos longifrons, Owen 554 



Mr. G. W. Ormerod on the Geology of the upper part of 



the Valley of the Teign, Devonshire 555 



Mr. G. Clark on the Geological Features of Mauritius . . 555 



