RECENT PAPERS IN THE ‘PHILOSOPHICAL TRANSACTIONS.’ 
Series A.—Mathematical and Physical. 
A 594. The Emission of Electrons under the Influence of Chemical Action. By O. W. Richardson,, 
F.R.S., Wheatstone Professor of Physics, University of London, King’s College. Pp. 43. 
Price 4s. 
A 595. The Problem of Finite Focal Depth revealed by Seismometers. By George W. Walker, , 
A.R.C.Sc., M.A., F.R.S., formerly Fellow of Trinity College, Cambridge, Pp. 12. Price Is. 6d. 
A 596. Eddy-Current Losses in Cylindrical Conductors, with Special Applications to the Alternating 
Current Resistances of Short Coils. By S. Butterworth, M.Sc. Pp. 44. Price 4s. 
A 597. The Influence of Satellites upon the Form of Saturn’s Ring. By G. R. Goldsbrough, D.Sc., 
Armstrong College, Newcastle-on-Tyne. Pp. 30. Price 2s. 
A 598. The Analysis of Sound.—Part I. The Experimental Analysis of Sound in Air and Water: Some 
Experiments towards a Sound Spectrum. By Guy Barlow, D.Sc. (Wales, Lond., Birm.), 
F.Inst.P., Lecturer in Physics in the University of Birmingham, and H. B. Keene, D.So. 
(Birm.), F.Inst.P., Lecturer in Physics in the University of Birmingham. Part II. The 
Theory of Analysis of an Electric Current by Periodic Interruption. By Guy Barlow, D.Sc. 
Pp. 36. Price 3s. 
A 599. Lagrange’s Ballistic Problem. By A. E. H. Love, F.R.S., Sedleian Professor of Natural 
Philosophy in the University of Oxford, and F. B. Pidduck, M.A., Fellow of Queen’s College, 
Oxford. Pp. 60; 2 Plates. Price 5s. 
A 600. The Aerodynamics of a Spinning Shell.—Part II. By R. H. Fowler and C. N. H. Lock. 
Pp. 21. Price 2s. M. 
A 601. Bakerian Lecture. —Optical Rotatory Dispersion.—Part II. Tartaric Acid and the Tartrates. 
By Thomas Martin Lowry, F.R.S., and Percy Corlett Austin. Pp. 60. Price 7s. 6d. 
Series B. — Biological. 
B 378. On the Structure and Affinities of Acmopyle Pancheri, Pilger. By Birbal Sahni, M.A., M.Sc., 
University Professor of Botany, Lahore (Punjab); late Professor of Botany at the Hindu 
University, Benares City, India. Pp. 58; 3 Plates. Price 10s. 6 d. 
B 379. On the Calcification of the Vertebral Centra in Sharks and Rays. By W. G. Ridewood, D.Sc. 
Pp. 97. Price 10s. 
B 380. The Life-History and Cytology of Synchytrium Endobioticum (Schilb.), Perc., The Cause of 
Wart Disease in Potato. By K. M. Curtis, M.A., M.Sc., D.I.C., F.L.S. Pp. 70; 5 Plates. 
Price 10s. 6 d. 
B 381. Title, Contents, Index, &c., Vol. 210. Pp. 10. Price Is. 
Volume 210 (1921), 480 pp., with 16 Plates, Price £3 5s. 6 d. 
B 382. On a Periodic Structure in many Insect Scales, and the Cause of their Iridescent Colours. By 
H. Onslow. Pp. 74; 3 Plates. Price 10s. 6 d. 
B 383. The Asymmetry, Metamorphosis and Origin of Flat-Fishes. By H. M. Kyle. Pp. 55; 7 Plates. 
Price 10s. 
B 384. Regeneration and Reproduction of the Syllid Procerastea. By E. J. Allen, D.Sc., F.R.S., Director 
of the Plymouth Laboratory. Pp. 47 ; 6 Plates. Price 17s. 6 d. 
B 385. The Breeding Places of the Eel. By Johs. Schmidt, D.Sc., Copenhagen. Pp. 30; 2 Plates. 
Price 4s. 
Cloth cases for binding the volumes of the ‘ Philosophical Transactions.’ Price 3s. 6 d. 
Published for the EOYAL SOCIETY by 
Harrison and Sons, Ltd., 44-47, St. Martin’s Lane, London, W.C. 2. 
