CONTENTS. V 



Page 



NUMBER XXL— SEPTEMBER. 



Mr. Rob. Brown's brief Account of Microscopical Observations 

 made in the Months of June, July, and August, 1827, on 

 the Particles contained in the Pollen of Plants ; and on the 

 general Existence of active Molecules in Organic and Inor- 

 ganic Bodies 161 



M. Steinheil on a New Micrometer, principally intended for 



the Construction of a more complete Map of the Heavens 173 

 Mr. Galbraith's Comparison of a Formula representing the 

 Velocity of Sound, with Capt. Parry and Lieut. Foster's Ex- 

 periments on that Subject at Port Bowen ; with some Re. 



marks on the Ellipticity of the Earth 179 



J.L.T. on the Reduction of CircummeridianAltitudes of the Sun 182 



Dr. Hare's Improved Eudiometrical Apparatus 183 



Dr. Hare on the Litrameter 187 



Mr. Ivory on Measurements on the Earth's Surface perpendi- 

 cular to the Meridian 189 



Mr. De la Beche on the Tables of Oltmanns for calculating 

 Heights by the Barometer, rendered applicable to English 



Barometers and Measures • • • 194? 



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 .... 206 



Mr. Graham on the Influence of the Air in determining the 



Crystallization of Saline Solutions 215 



Mr. Nixon's Method of avoiding certain sources of inaccuracy 



in the use of Kater's Horizontal Floating Collimator 218 



Mr. Gray's Description of a new Kind of Pear-Encrinite found 



in England 219 



New Books : — Watkins'sPopularSketch of Electro-Magnetism, 



or Electro-Dynamics 220 



Proceedings of the Geological Society 222 



. Medico-Botanical Society 227 



Tubes formed by Lightning— Artificial Ultramarine 228 



Mellitic Acid 229 



M. Fischer on the Action of Acids on Palladium 230 



M. Brandes's Preparation of Conia, the Alkali of the Conium 



Maculatum — On Pyrophorus 23 1 



Effect of Ebullition upon Cupreous Salts 232 



Boruret of Iron— Varieties of Borax — Figure of the Cells of 



the Honeycomb 233 



Mr. Buchan's Experiments on the Amalgamation of Silver- 

 Ores — Mr. Otley's Account of a cheap and easily-construct- 

 ed Barometer for measuring Altitudes, &c 234 



Nummulites in the Green-sand Formation 235 



Fossil Herbivorous Reptiles — Solar Spots 236 



New Patents 237 



Meteorological Observations , 238 



Meteoro- 



