CONTENTS OF VOL. XXXIV.— THIRD SERIES. Vll 



Page 



M. Duhamel on the Multiple Sounds of Bodies 415 



Sir W. R. Hamilton on Quaternions ; or on a New System of 



Imaginaries in Algebra (continued) 425 



M. Ch. Matteucci's Further Researches on Electro- Physiology 440 

 Mr. S. M. Drach's easy Rule for Formulizing all Epicyclical 



Curves with one moving circle by the Binomial Theorem. . . . 444 

 The Rev. J. Challis on Spherical Waves in an Elastic Fluid, 



in reply to Mr. Stokes 449 



Prof. Pliicker on the Magnetic Relations of the Positive and 



Negative Optic Axes of Crystals 450 



Notices respecting New Books : — Sir J. F. W. Herschel's Out- 

 lines of Astronomy 452 



Proceedings of the Cambridge Philosophical Society 455 



Royal Astronomical Society 459 



Royal Society 463 



On some Meteorological Phsenomena, by Prof. E. Wartmann 469 

 On the Reflexions of different kinds of Heat by Metals, by 



MM. F. De la Provostaye and P. Desains . . . .' 471 



On Chloroniceic Acid, by M. E. Saint-Evre 473 



On the Nature and Composition of various Chloroniceates, by 



M. E. Saint-Evre 474 



On the Reaction of Sulphate of Potash and Sulphate of Copper, 



by M. J. Persoz 475 



On Octohedral and Cubic Alum, by M. J. Persoz 476 



On Anisol and its Derivatives, by M. A. Cahours 476 



Compounds of Hydrochlorate of Strychnia and Cyanide of Mer- 

 cury 479 



Meteorological Observations for April 1849 479 



Table 480 



NUMBER CCXXXIL— SUPPLEMENT TO VOL. XXXIV. 



M. A. Bertin on Circular Magnetic Polarization 481 



Mr. G. G. Stokes on the Theory of Sound , 501 



Mr. Reuben Phillips on the Magnetism of Steam 502 



Prof. Challis on some Points relating to the Theory of Fluid 



Motion 512 



Appendix to Mr. Drach's Paper on Epicyclic Curves in the last 



June Number 520 



Sir R. I. Muichison on the Distribution of the Superficial De- 

 tritus of the Alps, as compared with that of Northern Europe 523 



Mr. A. Cayley's Note on the Theory of Permutations 527 



Proceedings of the Royal Society 529 



■ Royal Astronomical Society 532 



Deflection of the Magnetic Needle by the Act of Volition .... 543 

 On the Artificial Formation of Minerals in the Humid Way, by 



M. de Senarmont 545 



Index '. 547 



