IV CONTENTS. 



Page 



Sir H. Davy on the Phaenomena of Volcanoes 85 



Dr. Hare'sRationale of the Difficulty of separating Plane Sur- 

 faces by a Blast, in certain Cases 94? 



Dr.Turner's Chemical Examination of the Oxides of Manganese 96 



Prof. Gauss's General Solution of the Problem : to represent 



the Parts of a given Surface on another given Surface, so 



that the smallest Parts of the Representation shall be similar 



to the corresponding Parts of the Surface represented (con- 



tinned) 104* 



Prof. Del Rio's Analysis of two new Mineral Substances, con- 

 sisting of Bi-seleniuret of Zinc and Sulphuret of Mercury, 



found at Culebras in Mexico 113 



Mr. Pentland's Observations on the Peruvian Andes, in reply 

 to a Paper by M. Coquebert de Montbret, in the Annates 



des Scie)ices Naturelles 115 



Mr. J. de C. Sowerby on the Penetration of Water into stop- 

 pered and corked Bottles sunk to a great Depth in the Sea 119 

 Dr. Prout's further Remarks on Messrs. Tiedemann and 



Gmelin's Observations on the Acids of the Stomach 120 



Mr. Sharpe on the vitrified Fort of Dunnochgoil, in the Isle of 



Bute 123 



Mr. Seers's Method of solving adfected Quadratic Equations 125 

 Dr. Hare's Improved Eudiometrical Apparatus (continued) . . 126 

 New Books : — Rev. Dr. Pearson's Appendix to the First Volume 

 of An Introduction to Practical Astronomy ; — Dr. Harwood 

 on the Curative Influence of the Southern Coast of England 134? 



Proceedings of the Astronomical Society 136 



' Royal Academy of Sciences of Paris. ... 139 



New Astronomical Ephemeris • 14?1 



Mr. Dunn's Improved Air-Pump 145 



Gallates of Quina and Cinchonia — Preparation and Properties 



of Aluminum 147 



Chloride and other Compounds of Aluminum 149 



Native Iodide of Mercury — Corydalin, a new Vegetable 



Alkali 151 



Action of Alkalies and their Carbonates, &c. on Iodides — Citric 



Acid from Gooseberries 152 



Solanine — Blue Colour by the Action of Muriatic Acid upon 

 Albumen — Botryogene, or Native red Iron-vitriol of Fahlun 153 



Erinite, a new Mineral Species 154? 



Alteration of Crystalline State in Solids—Decomposition of 



Ammonia by Metals — Iodides of Carbon 155 



Solar Spots 156 



New Patents— Mr. Herapath 157 



Meteorological Observations * 158 



made at the Garden of the Hor- 

 ticultural Society at Chiswick, near London, by Mr. Giddy 

 at Penzance, Dr. Burney at Gosport, and Mr. Veall at Boston 160 



NUMBER 



