iv Contents. 



No. PAGE 



XII. — The Change of Length in Nickel Wires due to Transverse 

 Magnetic Fields Direct and Alternating. By William 

 Brown, b.sc. (May, 1916.) . . . .121 



XIII. — The Subsidence of Torsional Oscillations of Nickel and Iron 

 Wires when subjected to the Influence of Transverse Mag- 

 netic Fields up to 800 C.G.S. Units. By William Brown, 

 b.sc. (May, 1916.) ..... 125 



XIV. — Note on Laminated Magnets. By William Brown, b.sc. 



(June, 1916.) . . . . . .137 



XV. — On the Mode of Occurrence and Origin of the Orbicular Granite 

 of Mullaghderg, Co. Donegal. By Grenville A. J. Cole, 

 m.r.i.a., f.g.s. (Plates IV-V.) (October, 1916.) . . 141 



XVI. — An Abnormality in the Arterial System of the Babbit. By 



Edmond J. Sheehy, a.r.c.sci. (December, 1916.) . . 159 



XVII. — The Fatigue of Nickel and Iron Wires when subjected to the 

 Influence of Transverse Alternating Magnetic Fields. By 

 William Brown, b.sc. (January, 1917.) . . . 163 



XVIII. — The Chemistry of Foul Mud Deposits. By E. A. Letts, d.sc, 



&c, and Florence W. Bea, b.sc. (January, 1917.) . 171 



XIX. — Award of the Boyle Medal to Professor Henry Horatio Dixon, 



scd., f.r.s., 1916. (February, 1917.) . . .179 



XX. — The Change in Young's Modulus of Nickel with Magnetic Fields. 



By William Brown, b.sc (April, 1917.) . . . 185 



XXI. — Further Observations on the Cause of the Common Dry-Bot of 

 the Potato Tuber in the British Isles. By George H. 

 I'ethybridge, b.sc, ph.d., and H. A. Lafferty. (Plates VI- 

 VII.) (June, 1917.) . . . . .193 



XXII. — The Gymnosomatous Pteropoda of the Coasts of Ireland. By 



Anne L. Massy. (Plate VIII.) (July, 1917.) . . 223 



XXIII. — Spermolithus Devonicits, gen. et sp. nov., and other Pteridosperms 

 from the Upper Devonian Beds at Kiltorcan, Co. Kilkenny. 

 By Thomas Johnson, d.sc, f.l.s. (Plates IX-XIV.) (August, 

 1917.) . . • ■ • • .245 



XXIV. — The Genus 1'aenitis, with some Notes on the remaining 

 Taeniticlinae. By Elizabeth J. Leonard, m.sc. (Plate XV.) 

 (February, 1918). . . # . . .255 



XXV. — The Quantitative Spectra of Lithium, Bubidium, Caesium, and 

 Gold. By A. G. G. Leonard, a.r.c.sci., b.sc, ph.d., and 

 P. Whelan, a.r.c.sci. (Plate XVI.) (February, 1918.) . 274 

 XXVI. — The Polarisation of a Leclanche Cell. By Felix E. Hackett, 



ph.d., and B. J. Feely, a.r.c.sci. (March, 1918.) . . 279 



