Index. 
261 
Houstoun (R. A.)- The Absorption of X-Rays, 
34-42. 
Note on the Scattering of X-Rays, 43-50. 
Howie (William Lamond), Obituary Notice of, 4. 
Identities, Vectorial, by F. L. Hitchcock, 129- 
139. 
Index of Papers published in Transactions, 
1919-20, 263. 
Jackson (Sir John), Obituary Notice of, by 
D. A. Stevenson, 182-184. 
Jones (Geo. Wm. ), Obituary Notice of, 5. 
Keith Prize, 1917-19, to Prof. J. Stephenson, 
205. 
Kidston (R.) and W. H. Lang. Old Red Sand- 
stone Plants showing Structure, from the 
Rhynie Chert Bed, Aberdeenshire, Part III. 
( Title only), 203. 
King (Andrew), Obituary Notice of, 5. 
Knott (C. G. ) and Miss Dallas. Magnetic 
Strains in Nickel Steel Tubes. {Title only), 
204. 
Lang (W. H.). See Kidston (R. ). 
Law of Force giving Stability to the Rutherford 
Atom, by J. Marshall, 150-157. 
Laws, 253. 
Changes in, 204, 205. 
Le Harivel (Miss), Resignation of, 207. 
Library, Additions to (Gift or Purchase), 249. 
Binding in, Grant from Carnegie U.K. 
Trust, 207. 
Macalister (Alexander), Obituary Notice of, 194. 
Macdonald (Rt. Hon. Sir J. H. A.), Obituary 
Notice of, 5-7. 
Maclagan (R. C.), Obituary Motice of, 7. 
Malaria, Harmala Alkaloids in, by J. A. Gunn 
and D. G. Marshall, 140-149. 
Marsden (R. Sydney), Obituary Notice of, 7. 
Marshall (D. G.). See Gunn (J. A.). 
Marshall (J.). An Unnoticed Point in the 
Theory of Newton’s Rings, 51-55. 
A Law of Force giving Stability to the 
Rutherford Atom, 150-157. 
Mathematics, National Union of, Representa- 
tives, 207. 
Matrices, Determinant whose Matrix is the Sum 
of Two Circulant, by Sir Thomas Muir, 23-32. 
Meetings of the Society, Proceedings of the 
Ordinary, 1919-20, 203. 
Proceedings of the Statutory, 199, 207. 
Menzies (Alan W. C. ). The Explanation of 
an apparent Anomaly outstanding in the 
Results of Measurement of Dissociation 
Pressures, 158-160. 
Meteorological Committee Air Ministry, 207. 
Mirage at Ingatestone, by G. F. Quilter, 38. 
Mitchell-Thomson (Sir M.), Obituary Notice 
of, 8. 
Molecular Energy in Gases, by Sir J. A. Ewing, 
102 - 111 . 
Muir (Sir Thomas). Note on the Determinant 
whose Matrix is the Sum of Two Circulant 
Matrices, 23-32. 
Muir (Sir Thomas). Note on Pfaffians with 
Polynomial Elements, 83-88. 
Musical Scale, by Joseph Goold, 161-171. 
Newton’s Rings, Unnoticed Point in the Theory 
of, by J. Marshall, 51-55. 
Neill Prize, 1917-19, to Prof. John Tait, 
206. 
Obituary Notices of Fellows, 1-9, 182-195. 
Papers, List of, read during Session 1919-20, 
203-206. 
Peddie(W.). On the Quaternionic System as 
the Algebra of the Relations of Physics and 
Relativity, 80-82. 
Atomic Space Lattice in Magnetite. 
{Title only), 203. 
The Adequacy of the Young-Helmholtz 
Theory of Colour- Vision and Colour- Blindness. 
{Title only), 204. 
Pfaffians with Polynomial Elements, by Sir 
Thomas Muir, 83-88. 
Phillips (Frederick), Obituary Notice of, 8. 
Physics and Relativity, Quaternionic System 
and, by W. Peddie, 80-82. 
Pickering (Ed. Charles), Obituary Notice of, 1. 
Polynomial Elements, Pfaffians with, by Sir 
Thomas Muir, 83-88. 
Pressures, Dissociation, Explanation of Anoma- 
lous Results in Measuring, by Alan W. C. 
Menzies, 158-160. 
Prince of Wales elected Hon. Fellow, 205. 
Prizes, Conditions governing, and Awards, 
210-218. 
Proceedings of the Ordinary Meetings, 1919-20, 
203. 
Proceedings of the Statutory Meetings, 1919-20, 
199, 207. 
Quaternionic System and Physics and Relativity, 
by W. Peddie, 80-82. 
Quilter (G. F.). Note on Mirage at Ingate- 
stone, 33. 
Radio-Telegraphy, National Union of, 207. 
Ramsay (Edward P. ), Obituary Notice of, 
194. 
Rayleigh (Lord), Obituary Notice of, 2. 
Redwood (Sir Boverton), Obituary Notice of, 
8 . 
Reports of the General Secretary, 1919-20, 
199, 207. 
Retzius (Gustaf), Obituary Notice of, 2. 
Rutherford Atom, Law of Force giving Stability 
to, by J. Marshall, 150-157. 
Sachs (Edwin O. ), Obituary Notice of, 9. 
Sampson (R. A.). Addresses on “Theory of 
Gravitation.” {Titles only), 203. 
Sawyer (Sir James), Obituary Notice of, 9. 
Secretary’s Reports, 1919-20, 199, 207. 
Sherriff (Catherine W. M.). On a Class of 
Graduation Formulae, 112-128. 
Soil, Cooling of, at Night, by T. B. Franklin, 
10 - 22 . 
Soil Temperatures, The Effect of Weather 
Changes on, by T. B. Franklin, 56-79. 
