CONTENTS. m 



Page 



XXVII. Notice of Mr Christie's Discoveries respecting the Effect of Rotation 



on the Magnetic Forces, - - - . - 135 



XXVIII. Analysis of a Mica from Cornwall. By Edwahd Turner, M. D. 

 F. H. S. E. &c. Lecturer on Chemistry, and Fellow of the Royal College 



of Physicians, Edinburgh. Communicated by the Author, - 137 



XXIX. ZOOLOGICAL COLLECTIONS, - - - 143 

 1. Conybeare on the Plesiosaurus. 2. Discovery of the Megalosaurus. 



3. Gigantic Fossil Coral. 4. Enormous Orang-Outang found in Su- 

 matra. 5. Aranea Domestica, possessed of a Natural Diving Bell to 

 assist It in Crossing Water. 6. Mode of Catching Fish by Diving, pe- 

 culiar to the Gulf of Patrasso. 7- Rapidity of the Effects of the Poison 

 of some of the New Holland Snakes. 8. On Changing the Residence 



of Fishes. 9. Structure of the Hind-Foot of the Walrus, 143 146 



XXX. DECISIONS ON DISPUTED INVENTIONS AND DISCO- 



VERIES, 14C 



I. The Rediscovery of the Comet of Encke due to Mr Rumker, and not to 

 Mr Dunlop. 2. The Composite Structure of the Bipyramidal Sulphate 

 of Potash not discovered by Mr Brooke. 3. The apparent Immobility 

 of Spectral Impressions ; their Singleness by Distorted Vision ; and the 

 Reference of the Phenomena of Vision to Voluntary Muscular Action, 

 first discovered and proposed by Dr Wells, and not by Mr Charles Bell. 



4. Professor Leslie's Hygrometer, invented by the late Dr James Hut- 

 ton, - . .... 146—149 



XXXI. HISTORY OF MECHANICAL INVENTIONS AND PRO- 



CESSES IN THE USEFUL ARTS, - - ]49 



1. British Invention and Discovery Association, - - ib. 



2. Mr Bryce's Stomach or Moveable Branch Syphon, - . ib. 

 3- Mr Shiells' Triangle for Elevating the Jet of Fire Engines, . 150 



4. Account of an improved Hydropneumatic Lamp, which can be con- 

 structed at a small expence. By William Dyce, M. D. F. R. S. Ed. 151 



5. On the Use of Granite for Railways. In a Letter from John Gibb, 

 Esq. Civil Engineer, to John Robison, Esq. F. R. S. E. - 152 



6. Description of a Single Valve Sluice, invented by Robert Thom, 

 Esq. Rothsay, . . . - _ - 154 



7. Description of a Chain Sluice, invented by Robert Thom, Esq. 

 Rothesay, - . . . . . -155 



8. Description of a Breathing-Pump, invented by William Van Hou- 

 ten, Junior, Rotterdam, - - - . 150 



9. Professor Amici's Improved Camera Lucidas, - . 157 



XXXII. ANALYSIS OF SCIENTIFIC BOOKS AND MEMOIRS, 159 



I. The English Flora. By Sir James Edward Smith, President of 

 the Linnean Society. 2 vols. 8vo. - - - - ib. 



II. On the Effects of the Density of Air on the Rates of Chronometers. 

 By George Harvey, Esq. F. R. S. E., &c. From the Philosophical 

 Transactions for 1824, Part II. - ... 170 



