CONTENTS.
VOL. XV.
Page
On the Colouring and Extractive Matters of Urine. — Part I. By Edward Schunck, F.R.S 1
Sixth Memoir on Radiation and Absorption. By Professor J. Tyndall, F.R. S. 5
On the Spectrum of Comet 1, 1866. By William Huggins, F.R.S ih.
Note on the Secular Change of Magnetic Dip, as recorded at the Kew Ob- servatory. By Balfour Stewart, M.A., LL.D, F.R.S., Superintendent of the Observatory 8
On the Specific Gravity of Mercury. By Balfour Stewart, M.A., LL.D., F.R.S., Superintendent of the Kew Observatory 10
On the Forms of Graphitoidal Silicon and Graphitoidal Boron. By W. H. Miller, M.A., For. Sec. R.S., and Professor of Mineralogy in the Univer- sity of Cambridge 11
On the Viscosity or Internal Friction of Air and other Gases, being the Ba- kerian Lecture, delivered by James Clerk Maxwell, M.A.^ F.R.S 14
Further Observations on the Spectra of some of the NebulEe, with a Mode of determining the Brightness of these Bodies. By William Huggins, F.R.S 17
Account of Experiments on the Flexural and Torsional Rigidity of a Glass Rod, leading to the determination of the Rigidity of Glass. By Joseph D. Everett, D.C.L., Assistant to the Professor of Mathematics in the Uni- versity of Glasgow 19
Note on the relative Chemical Intensities of direct Sunlight and difiuse Daylight at Different Altitudes of the Sun. By Henry E. Roscoe, F.R.S., and Joseph Baxendell, F.R.A.S 20
Researches on Acids of the Lactic Series. — No. I. Synthesis of Acids of the Lactic Series. By E. Frankland, F.R.S., and B. F. Duppa, Esq 25
Note on a Correspondence between Her Majesty's Government and the Pre- sident and Council of the Royal Society regarding Meteorological Obser- vations to be made by Sea and Land. By Lieutenant-General Sabine, P.R.S 29
On the Action of Compasses in Iron Ships. By Mr. John Lilley 38
On the Tidal Currents on the West Coast of Scotland. By Archibald Smith, M.A., F.R.S 42
