TABLE OF CONTENTS. 



Thomas Davidson, Esq., F.K.S., Sec. G.S., &c. — Palasontological Notes on 



the Brachiopoda - " " 

 H. S., Plymouth. — On Rocks ; their Chemical and Mineral Composition, and 



Physical Characteristics 416 



Key. T. W. Norwood, Cheltenham. — The Comparative Geology of Hotham, 



near South Cave, Yorkshire 420 



The Spirit of Good Books. — Cambridge Essays, 1857. — Hopkins' Geology - - 426 



Dr. T. L. Phtpsox. — Foreign Correspondence 432 



T. Rupert Jones, F.G.S. — Notes on Making Gutta Percha Moulds and Plaster 



of Paris Casts 436 



Reports of Geological Societies 437 

 Notes ajnd Queries - 439 



British Association Meeting 450 



Reviews 452 



A GEICULTUR AL AKD CHEMICAL COLLEGE, 



38 and 39, Lower Kenniugton-lane, Loudon. 

 Principal— J. C. NESBIT, F.G.S., F.C.S., &c. 

 In this Institution unusual facilities are afforded for acquiring a thorough 

 knowledge of agricultural, general, and analytical chemistry, and also of surveying 



and mathematics. 



The terms for students, resident or non-resident, may be known on application. 

 Analyses and assays of evei-y description are promptly and accurately executed at 

 the College. 



TO TOURISTS INT NORTH WALES.— The Geological Structure of 

 Merionethshive and Carnarvonshire," by Professor A. Ramsay, F.R.S., and G.S. 

 Illustrated by a Panoramic Diagram, drawn from the summit of Cader Idris, by 

 Percy W. Hengill, Esq., C.E., reprinted, with additions, from the Geologist, VoL I, 

 No. 5, 1858. Cloth Is 6d., stitched Is. 



London: Reynolds and Co., 15 Old Broad- street ; Simpkin, Marshall, and Co., 

 Stationers' Hall court. 



DOUBLE REFRACTING SPAR.— Mr. Tennant, Geologist, 149 Strand, 

 has just received from Iceland some unusually large and fine specimens of this 

 interesting mineral. Mr. Tennant arranges Elementary Collections of Shells, 

 Minerals, Rocks, and Fossils, to illustrate Conchology, Mineralogy, and Geology. He 

 also gives Practical Instruction in Geology and Mineralogy. 



Just Published, price One Shilling. 



QN THE EXTRACTION of the PRECIOUS METALS, by means of 

 IMitchell's Patented Amalgamating Machinery. Also a description of the various 

 .modes at present in use for the treatment of Auriferous and Argentiferous substances. 

 By .John MitcheU, F.C.S. , Author of " Manual of Practical Assaying," " Metallui-gical 

 Papers," &c. 



To be had of Percival Clay, 37 Old Broad Street, London, E.C. 



J\ibt published, 8vo., 3s. 6d., sewed, 

 ^VKE GROUND BENEATH US: its Geological Phases and Changes. 



Being three lectures on the geology of Clapham and the neighbom-hood of 

 London generally. By Joseph Prestwich, F.R.S., F.G.S., &c. John Van Voorst, 

 1 Paternoster Row. 



piiO\ INCIAL INSTITL^TIONS desirous of making armngeinents for 

 the delivery, during the ensuino; season, of popular lectures on Geology, are 

 requested to communicate with the Editor of the Geologist during the present 

 mouth. 



