CONTENTS 



, 



On a peculiar class of Optical Deceptions. By M. FARADAY, F.R.S. 



Director of the Laboratory of the Royal Institution, &c. . 205 



Description of a Mode of erecting light Vaults over Churches and 

 similar Spaces. ByM. DE LASSAUX. [Communicated by Pro- 

 fessor WHEWELL, of Cambridge] . . . .224 

 Account of a New Comet observed by M. DABADIE . .241 

 On the Permanence of the Magnetism in Steel Bars. By S. H. 



CHRISTIE, Esq., M.A., F.R.S., &c. . . . 243 



On the Electro -Chemical Decomposition of the Vegeto- Alkaline 

 Salts. By W. T. BRANDE, F.R.S., Prof. Chem. R. I. . .250 



Some Observations on Dr. Arnott's Explanation of the Nature of 

 Stammering. By MARSHALL HALL, M.D., F.R.S., &c. . 253 



Observations on Mr. Rennie's Paper on the peculiar Habits of 

 Cleanliness in some Animals. By WILLIAM AINSWORTH, 

 Esq 261 



On the Aurora Borealis of the 7th of January, 1831. By S. H. 



CHRISTIE, Esq., M.A., F.R.S., &c. .... 262 



On the Mechanism of the Act of Vomiting. By MARSHALL HALL, 



M.D., F.R.S.E., &c. . . . . .265 



Further Experiments on the Communication of Phosphorescence 

 and Colour to Bodies by Electricity. By THOMAS J. PEARSALL, 

 Chem. Assist, in the Laboratory of the Royal Institution . 267 



On the Darkness between the Primary and Secondary Rainbows. By 

 Mr. AINGER. [In a Letter to M. FARADAY, Esq., F.R.S., &c.] 281 



On the Mode of Ascertaining the Commercial Value of Ores of 

 Manganese. By EDWARD TURNER, M.D., F.R.S. L. and E., 

 Sec. G.S., Prof. Chem. in the University of London. . . 293 



Phenomena observed at the last Eruption of Mount Vesuvius in 



1828. By Dr. E. DONATI . . . . .296 



VOL. I. FEB. 1831. b 



