CONTENTS. vil 
(Part SEconp.) 
XV. On the Effects of Compression and Dilatation in al- 
tering the Polarising Structure of Doubly Re- 
fracting Crystals. By David Brewster, LL. D. 
F. RB. S. Lond. & Edin. - - Page 281 
XVI. Experiments on Muriatic Acid Gas, with Observations 
on its Chemical Constitution, and on some other 
Subjects of Chemical Theory. By John Murray, 
M. D. F. R. S. Edin. - - 287 
XVIL Experiments on the Relation between Muriatic Acid 
and Chlorine; to which is subjoined the Descrip- 
tion of a New Instrument, for the Analysis of 
Gases by Explosion. By Andrew Ure, M. D. 
Professor of the Andersonian Institution, and 
Member of the Geological Society, . 329 
XVUL On the Laws which regulate the Distribution of the 
Polarising Force in Plates, Tubes, and Cylinders 
of Glass, that have received the Polarising Siruc- 
ture. By David Brewster, LL. D. F. R. S. Lond. 
and Edin. - - 353 
XIX. Remarks, illustrative of the. Scope and Influence of 
the Philosophical Writings of Lord Bacon. By 
Macvey Napier, Esq. F.R.S. Lond.;& Edin. 
vnd F.A.S. Edin. - 3 373 
XX. Sketch of the Geology of the Environs of Nice. By 
Thomas Allan, Esq. F. R. S. Edin. S = Aly 
XXI. On certain Impressions of Cold transmitted from the 
Higher Atmosphere, with the Description of an 
Instrument adapted to measure them. By John 
Leslie, F. R. S. Edin. and Professor of Mathema- 
tics in the University of Edinburgh. - - 465 
XX. 
