CONTENTS OF VOL. XXII. 
Vv 
Page 
Mr. J. P. Joule on the Electrical Origin of Chemical Heat.... 204 
Sir Graves C. Haughton’s Experiments in Electricity ...... 208 
Mr. R, Warington on the Biniodide of Mercury . - 209 
Sir D. Brewster on the Cause of the Colours in iridescent Agate 213 
Lieut. Newbold on the Geology of Egypt ey a) 
Proceedings of the Geological Society...........:e++00--- 226 
——__—_—_———- Royal Astronomical Society. . 228 
—_——_-———— London Electrical Society. . . 232 
—— Literary and Philosophical Society of Liver- 
Picci SAA OTOH CIC Oe IA CME SEO ODIO LE Ae ieaet Ciena ae 232 
On the Discovery of Native Lead in Ireland, Be Mr. T. eee 
Jun.. uae 234 
On the ‘Composition of Paka’ by M. ‘Lewy BE re theatre 235 
Analysis of Human Bones, by Berzelius and by Marchand.... 236 
Compounds of Phosphoric Acid with Oxide of Lead, by M. 
(AYE AGORA re Oe eA | inh ee eee 237 
New Method of precipitating Metals in the State of Sulphuret, 
Raven cue Meigs vues reo Sela te eo nto lelm a lage ace, orn. « 237 
Meteorological Observations for January 1843 ............ 239 
EDS chee ara e tere ea er outs 240 
NUMBER CXLV.—APRIL. 
The Rev. Baden Powell on Apparatus for the circular Polariza- 
iragos, aixOE 10k Eads vis e1 ues ested, alla 2. sicko es bbe & 98 241 
Sir John F. W. Herschel on the Action of the Rays of the Solar 
Spectrum on Vegetable Colours, and on some new Photogra- 
peice LOCESReS:( coneluited))2 «21553, 205% bake ic. Spiaisiok Gays irc 246 
Prof. J. R. Young’s New Criteria for the Imaginary Rvots of 
RapaMmACARNIIEL § ( COMEISTLAGLN coer baile 5rd? Gs (Lee Aaa SY Seid 252 
The Rev. Brice Bronwin on M. Jacobi’s Theory of Elliptic 
MMRBRED Soo 5 ios eet a et ameh sie deh becle Sath ® Date oie 258 
Professor Powell on Mr. Earnshaw’s Deduction of a Property 
Smenmenlarly Polarized Laght.(.).4)5 iat deiot tks dlewe «60d! 262 
Prof. Miller on the Form of Crystals of Tin .............. 263 
Mr. J. P. Joule on Sir G. C. Haughton’s Experiments in Elec- 
icity related in the last Number... s.0,2,.0% Sic 6 ci «0.0% 265 
A Correspondent on the Immersion of a small Spherical Ball in 
poet of high-pressure Steam. 05 ye0s se bee a dee 267 
Dr. Faraday on Dr. Hare’s Second Letter, and on the Che- 
mical and Contact ‘Theories of the Voltaic Battery. . 268 
Mr. R. Hunt’s Experiments and Remarks on the Changes 
which Bodies are capable of undergging in Darkness, and on 
the Agent producing these Changes.. .............. 000. 270 
Dr. J. Stenhouse on Pyrogallic Acid, and some of the Astrin- 
gent Substances which yield it 
@ Dine) 5 € Oe ws bs SLU 0 6 a, e's 2 ote 6 
