O u o »'SjL 
PROCEEDING'S 
OF THE 
ROYAL SOCIETY OF EDINBURGH. 
SESSION 1912-13. 
Part III.] VOL. XXXIII. [Pp- 225-316. 
CONTENTS. 
NO. PAGE 
XXI. On the Deviation of the Torsional Oscillations of Metallic 
Wires from Isochronism. By Professor W. Peddie . 225 
{Issued separately June 6, 1913.) 
XXII. The Effect of Thermal Treatment and the Effect of Longi- 
tudinal Strain in inducing a Sensitive State in certain 
Magnetic Materials. By Margaret B. Moir, M.A., B.Sc., 
Carnegie Research Fellow in the University of Glasgow. 
(i Communicated by Professor A. Gray, F.R.S.) . . 243 
{Issued separately July 4, 1913.) 
XXIII. Some New Types of Spectrophotometer on the “Flicker” 
Principle. By James Robert Milne, D.Sc. . . 257 
{Issued separately July 14, 1913.) 
XXIV. The Scattering of Light. By James Robert Milne, D.Sc. 
(With Two Plates) ...... 264 
{Issued separately July 16, 1913.) 
XXV. On the Compressibilities of Dilute Solutions of certain 
Inorganic Salts. By W. Watson, M.A., B.Sc., Carnegie 
Research Fellow in Physics, 1910-1912. ( Communicated 
by The General Secretary) ..... 282 
{Issued separately July 17, 1913.) 
EDINBURGH : 
Published by ROBERT GRANT & SON, 107 Princes Street, and 
WILLIAMS & NORGATE, 14 Henrietta Street, Covent Garden, London. 
