PROCEEDINGS 
OF THE 
ROYAL SOCIETY OF EDINBURGH. 
SESSION 1909-10. 
Part VII.] YOL. XXX. [Pp. 519-631. 
CONTENTS. 
NO. 
XXXVII. The Vapour Pressures of Mercury. By Alexander Smith 
. and Alan W. C. Menzies, . . . 
( Issued separately September 7, 1910.) 
XXXVIII. A Static Method for Determining the Vapour Pressures 
of Solids and Liquids. By Alexander Smith and 
Alan W. C. Menzies, ..... 
{Issued separately September 7, 1910.) 
XXXIX. 
XL. 
Did the Tail of Halley’s Comet affect the 
Atmosphere ? By Dr John Aitken, F.R.S., 
( Issued separately September 7, 1910.) 
Earth’s 
A Stereoscopic Illusion. By Professor Francis Gibson 
Bally, ALA., 
{Issued separately October 12, 1910.) 
XLI. The Efficiency of Metallic Filament Lamps. By R. A. 
Houstoun, M.A., D.Sc., Ph.D., Lecturer in Physical 
Optics in the University of Glasgow. {Communicated 
by Professor A. Gray, F.R.S.), . 
{Issued separately December 16, 1910.) 
XLII. On the Precipitation of Soluble Chlorides by Hydro- 
chloric Acid. By John Gibson, Ph.D., and R. B. 
Denison, D.Sc., Ph.D., . 
{Issued separately December 23, 1910.) 
PAGE 
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Obituary Notice : Daniel John Cunningham. By Professor C. G. 
Knott, ........ 
569; 
*,v- 
[ Continued on page iv of Cover. 
EDINBURGH: 
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