11 CONTENTS. 



Page 



Proceedings of the Royal Institution of Great Britain . .547 



Proceedings of the Academy of Sciences in Paris . . .558 



ANALYSIS OF BOOKS, AND SELECTIONS FROM THE TRANSACTIONS 

 OF SCIENTIFIC SOCIETIES. 



Life of Sir Humphry Davy, Bart., LL.D. . . . .571 



Acta Academiae Caes. Leop. Carol. Naturae Curiosae Bonnae . 585 



Memoirs of the Institute of France . . . .595 



FOREIGN AND MISCELLANEOUS INTELLIGENCE, 

 1. MECHANICAL SCIENCE. 



1. Stiffness and Strength of Timber .... 599 



2. Proportion between the Metre and English Yard . . ibid. 



3. On the Velocity of an Elastic Fluid which flows from a Reservoir into 



a Gasometer ...... ilrid. 



4. On the Discharge of a Jet of Water under Water (R. W. Fox, Esq.) ibid. 



5. Optical Deception upon the Liverpool and Manchester Rail Road 600 



6. A Barometer of a new Construction (Proposed by M. Kupffer.) . 601 



7. Occultation . . . . . . . ibid. 



8. Pendulum Observations ...... 602 



9. Dip of the Magnetic Needle at St. Petersburgh ... 604 



10. On the Direction and Intensity of the Magnetic Force at St. Peters- 



burgh (M. Erman) ...... ibid. 



11. Variation of the Needle ..... 607 



12. On the Figure of the Magnetic Equator .... ibid. 



13. New Dipping Needle ...... 608 



14. Powerful Electro-Magnets . . . .609 



15. On the Intensity of the Earth's Magnetism (Kupffer) . . 610 



II. CHEMICAL SCIENCE. 



1. Matteuci on the Origin of the Action of the Voltaic Pile . . 612 



2. Conducting Powers of Liquified Gases (K. T. Kemp) . .613 



3. Generation of Steam by Heated Metal . . . ibid. 



4. On the Preparation of lodic Acid (Serullas) . . . 614 



5. On the Precipitation of the Vegeto- Alkalies by lodic Acid (Serullas) 615 



6. On the Action of Bromic and Chloric Acids on Alcohol (Serullas) ibid. 



7. On Perchloric Acid and its Facil Formation (Serullas) . . 616 



8. On the Spontaneous Inflammation of Pulverized Charcoal (Aubert) . 617 



