CONTENTS. V 
Page. 
Professor Johnston on the physical Cause of certain Optical Proper¬ 
ties in Chabasie. 44 
Professor Graham on the constituent Water of certain Compounds. .. 45 
Professor Geoghegan on a new Method of testing the presence of Mu¬ 
riatic Acid in Hydrocyanic Acid. 45 
Mr. R. Mallet on Bleaching certain Varieties of Turf for the purpose 
of producing a White Fibre for the manufacture of Paper. 47 
Mr. R. Mallet on some singularPhaenomena of Flame from Coal-Gas 49 
Professor Daubeny on the Volatilization of Magnesia by Heat. 51 
Mr. FI. Hartop on the use of hot air in the manufacture of iron. 52 
Dr. Francis Barker’s Account of some Chemical Processes. 52 
The Rev. Wm. Vernon Harcourt on a Source of Inaccuracy in Ob¬ 
servations of the Dew-point. 54 
Mr. Moore on a peculiar Corrosion of a leaden Pipe. 55 
Mr. Ettrick on the Safety Lamp. 56 
Professor Graham on the Safety Lamp. 56 
Mr. W. Snow Harris on a new Electrometer. 56 
Report of the Committee appointed to consider the subject of Chemical 
Symbols. By Dr. Turner. 56 
GEOLOGY AND GEOGRAPHY. 
Mr. R. J. Griffith on the Geological Map of Ireland. 56 
Lieut. Stotherd on a small isolated Patch of Granite which occurs in 
the County of Cavan. 58 
Dr. Scouler’s Geological Map of the Environs of Dublin. 58 
Archdeacon Verschoyle on Eleven Trap Dykes in the Counties of 
Mayo and Sligo, running East and West for great distances. 59 
Dr. Jacob on certain Fossil Polyparia found in xllluvial Deposits in the 
vicinity of Limestone Hills. 59 
Professor Sedgwick and R. I. Murchison on the Silurian and Cam¬ 
brian Systems, exhibiting the order in which the older Sedimentary 
Strata succeed each other in England and Wales. 59 
Dr. Traill’s Notices of the Geology of Spain. 61 
Mr. H. Hartop on certain Disturbances in the Coal Strata of Yorkshire 
having a remarkable Relation to existing Valleys ; illustrated by a 
Map and Sections. 61 
M. Agassiz on Fossil Fish. 61 
Professor Phillips on British Fossil Astacidce , their Zoological and 
Geological Relations. 2. On British Belemnites. 62 
Professor Phillips’s Notice of a newly discovered Tertiary Deposit on 
the Coast of Yorkshire. 62 
Mr. C. Lyell’s Notice of the Shells in the Suffolk Crag. 63 
