VI CONTENTS OF VOL. XXIV. — TH1KD SERIES. 



Page 



Proceedings of the Royal Astronomical Society 300 



Geological Society 308 



Experiments on Coffee 313 



A new process for preparing Gallic Acid, by Edward N. Kent . 314 



Analysis of Melilite, by Mons. A. Damour 314 



Description and Analysis of Humboldtilite, and Identity with 



Melilite, by Mons. A. Damour 316 



Analysis of Guano, by MM. J. Girardin and Bidard 317 



Analysis of Pectic Acid, by M. Fromberg 319 



Meteorological Observations for February 1844 319 



Table.' '. 320 



NUMBER CLX.— MAY. 



Mr. G. S. Cundell on the practice of the Calotype Process of 



Photography 321 



The Rev. D. Williams on the Killas Group of Cornwall and 

 South Devon ; its relations to the subordinate formations in 

 Central and North Devon and West Somerset ; its natural 

 subdivisions; and its true position in the scale of British 



strata 332 



Prof. Grove on the Gas Voltaic Battery. — Experiments made 

 with a view of ascertaining the rationale of its action and 



its application to Eudiometry (continued) 346 



Mr. Reuben Phillips's Remarks on the Elasticity of Gases. . . . 354 

 Mr. T. Taylor on some new Species of Biliary and Intestinal 



Concretions 354 



Sir D. Brewster on the Law of Visible Position in Single and 

 Binocular Vision, and on the representation of Solid Figures 

 by the union of dissimilar Plane Pictures on the Retina. . . . 356 

 Mr. J. Napier on the Solubility of the Metals in Persulphate 



and Perchloride of Iron 365 



Mr. W. Herapath's Analyses of the Bath Waters and of the 



Bristol Hotwell Water* 371 



Mr. J. N. Furze's Observations on Fermentation 372 



Proceedings of the Geological Society 375 



Zoological Society 378 



■ Royal Irish Academy 380 



On Absinthic Acid, by C. Zwenger ..." 392 



Process for obtaining Osmium, by Mons. E. Fremy 393 



Examination of the African Guano, by E. F. Teschemacher . . 394 



Ratio of the Drachm and Grain, Avoirdupois 396 



Festival in honour of Berzelius 396 



Meteorological Observations for March 1844 399 



Table 400 



