XV1I1 



Observations on the Changes the Ovum of the Frog undergoes during 

 the formation of the Tadpole. By Sir Everard Home, Bart. 

 V.P.R.S page 227 



A general Method of calculating the Angles made by any Planes of 

 Crystals, and the Laws according to which they are formed. By the 

 Rev. W. Whewell, F.R.S. 227 



Explanation of an Optical Deception in the Appearance of the Spokes 

 of a Wheel seen through vertical Apertures. By P. M. Roget, M.D. 

 F.R.S 230 



On a new Photometer, with its application to determine the relative 

 Intensities of Artificial Light, &c. By William Ritchie, A.M 23^1 



The Dfscrjpfciou of a Floating Collimator. By Captain Henry Kater, 

 F.R.S. 232 



Notice on the Iguanodon, a newly discovered Fossil Reptile, from the 

 Sandstone of Tilgate Forest, in Sussex. By Gideon Mantell, F.L.S. 

 and M.G.S 234 



An experimental enquiry into the Nature of the radiant heating effects 

 from terrestrial sources. By Baden Powell, M.A. F.R.S 235 



On the Anatomy of the Mole-cricket. By J. Kidd, M.D. and F.R.S. 236 

 Further Observations on Planariae. By J. R. Johnson, M.D. F.R.S. 238 



On the Influence of Nerves and Ganglions in producing Animal Heat. 

 By Sir Everard Home, Bart. V.P.R.S 238 



An Essay on Egyptian Mummies ; with Observations on the Art of 

 . Embalming among the ancient Egyptians. By A. B. Granville, 

 M.D. F.R.S. F.L.S. F.G.S. M.R.I 240 



On the temporary Mas^netic Effect induced in Iron Bodies by Rota- 

 tion. By Peter Barlow, F.R.S. 241 



Further Researches on the Preservation of Metals by Electro-chemical 

 Means. By Sir Humphry Davy, Bart. P.R.S 242 



On the Magnetism of Iron arising from its Rotation. By Samuel 

 Hunter Christie, Esq. M.A 243 



Some Account of the Transit Instrument made by Mr. Dollond, and 

 lately put up at the Cambridge Observatory. By Robert Wood- 

 house, A.M. F.R.S ;: 246 



On the fossil Elk of Ireland. By Thomas Weaver, Esq 246 



Microscopical Observations on the Materials of the Brain, and of the 

 Ova of Animals, to show the analogy that exists between them. By 

 Sir Everard Home, Bart. V.P.R.S 247 



On new Compounds of Carbon and Hydrogen, and on certain other 

 Products obtained during the Decomposition of Oil by Heat. By 

 M. Faraday, F.R.S 248 



Account of the Repetition of M. Arago's Experiments on the Mag- 

 netism manifested by various Substances during the Act of Rota- 

 tion. By C. Babbage, Esq. F.R.S. and J. F. W. Herschel, Esq. 

 Sec. R.S 249 



On the Magnetism developed in Copper and other Substances during 

 Rotation. In a Letter from Samuel Hunter Christie, Esq. M.A. &c. 

 to J. F. W. Herschel, Esq. Sec. R.S 251 



