vill CONTENTS OF VOL. XXII, 
: Page 
Large Mass of Native Gold found in the Oural Mountains.... 499 
Fahlerz containing Mercury from Hungary ..............- - 500 
On Arsenio-Siderite, avariety of Arseniate of Iron, by M. Dufrenoy500 
Analysis of Chrysoberyl, by M. Awdejew .............-:- 501 
Solution of an Equation, by J. Cockle, Trin. Coll., Cambridge... 502 
On the Variation of Gravity in Ships’ Cargoes....... aes 503 
Meteorological Observations for April 1843 ............ .. 503 
OO SDDS SPCR Mi ctyis cer leletio ees, sn) 5,5 sia ce tenants »o O04 
NUMBER CXLVIIIL—SUPPLEMENT TO VOL. XXII. 
Sir John F. W. Herschel on certain improvements on Photo- 
graphic Processes described in a former Communication, and 
on the Parathermic Rays of the Solar Spectrum.......... 505 
Proceedings of the Geological Society ; Mr. Murchison’s Anni- 
versary Address, February 1843 2... 1... ee eee eres es CON) 
Proceedings of the Royal Astronomical Society...........- 567 
Meeting of the Royal Institution................-..+-84- 5470 
BHILOS ysis) SO oo fopeyes dive 1a Weta Rewie) ersasaiene oe ele) eae eee 571 
PLATES. 
I. Illustrative of Sir Jonn F. W. Herscuer’s paper on the Action of the 
Solar Spectrum on Vegetable Colours, inserted in the Philoscphical 
Magazine from January to April. 
II. Illustrative of Sir Joun F. W. Herscuet’s paper on the Action of the 
Solar Spectrum on Daguerreotype Plates. 
Il[. Illustrative of Dr. Drarer’s paper on a new System of inactive Titho- 
nographic Spaces in the Solar Spectrum. 
IV. Illustrative of Mr. Henwoon’s paper on the Appearances and Relative 
Positions of the Rocks and Veins which form the Opposite Walls of 
Cross-veins. 
ERRATA. 
P. 172, line 12, and p. 179, line 6, for [Plate II.] read [ Plate I.] 
P. 231, line 18, for M. Ertel, read M. Reichenbach. 
P. 497, 498, throughout the notice of M. Frémy’s researches on the 
oxides of lead, for plombic acid, plombates, and plombites, read 
plumbic acid, plumbates, and plumbites, respectively. 
