XV 



Remarks on M. de la Rive's Theory for the Physical Explanation of 

 the Causes which produce the Diurnal Variation of the Magnetic 

 Declination, in a letter to S. Hunter Christie, Esq. Sec. R.S., from 

 Lieut. -Col. Sabine, For. Sec. R.S page 821 



An appendix to a paper On the Variations of the Acidity of the Urine 

 in the State of Health " — " On the Influence of Medicines on the 

 Acidity of the Urine." By Henry Bence Jones, M.D. M.A. F.R.S. 

 &c. , 825 



On the direct production of Heat by Magnetism. By W. R. Grove, 

 Esq. M.A. V.P.R.S. &c 826 



On Carbonate of Lime as an ingredient of Sea-water. By John Davy, 

 M.D. F.R.S. Lond. and Ed., Inspector-General of Army- Hospitals, 

 &c 828 



On the Universal I^aw of Attraction, including that of Gravitation, as 

 a particular case of approximation deducible from the principle that 

 equal and similar particles of matter move similarly, relatively to 

 each other. By John Kinnersley Smythies, Esq 831 



On the Anatomy and Affinities of the Family of Medusss. By Henry 

 Huxley, Esq.' » 832 



Memoir to accompany a Map of the Magnetic Variation for 1840 in 

 the Atlantic Ocean between the parallels of 60° N. and 60° S. lati- 

 tude, being Contributions to Terrestrial Magnetism, No. 9. By 

 Lieut. -Colonel Edward Sabine, R.A. For. Sec. R.S .'. 835 



On the Microscopic Structure of the Scales and Dermal Teeth of some 

 Ganoid and Placoid Fish. By W. C. Williamson, Esq S37 



On the Mechanical Equivalent of Heat. By J. P. Joule, Cor. Asso- 

 ciate R. Acad. Sciences, Turin, &c 839 



On the Nitrogenous Principles of Vegetables as the sources of arti- 

 ficial Alkaloids. By John Stenhouse, F.R.S 840 



On the Development and Varieties of the great anterior veins in Man 

 and Mammalia. By John Marshall, Esq 842 



A Mathematical Theory of Magnetism. By William Thomson, M.A. 

 F.R.S.E., Fellow of St. Peter's College, Cambridge, and Professor 

 of Natural Philosophy in the University of Glasgow 845 



On the Nitroprussides, a new Class of Salts. Bv Dr. Lyon Playfair, 

 F.R.S. F.C.S ."' 846 



On the Structure of the Dental Tissues of Marsupial Animals, and 

 more especially of the Enamel. By John Tomes, Esq 847 



On the Motion of Gases.— Part II. By Thomas Graham, F.R.S. &c. 848 



On the Automatic Registration of Magnetometers and Meteorological 

 Instruments by Photography. — No. III. By Charles Brooke, M.B. 

 F.R.S 851 



On certain Properties of the Arithmetical Series whose ultimate differ- 

 ences are constant. By Sir Frederick Pollock, Lord Chief-Baron of 

 the Exchequer, F.R.S. &c 852 



On the Analysis of Numerical Equations. By J. R. Young, Esq., 

 Professor of Mathematics in Belfast College 854 



On some Phenomena and Motions of Metals under the influence of 

 Magnetic Force. By William Sykes Ward, Esq 855 



On the Diffusion of Liquids. By Professor Graham, F.R.S 897 



