CONTENTS 
I. On certain improvements on Photographic Processes described in a former Commu- 
nication, and on the Parathermic Raps of the Solar Spectrum. By Sir J. F. W. 
Herschel, Bart., K.H., F.R.S., 8$c. ; in a Letter addressed to S. Hunter 
Christie, Esq., Sec. R.S. Communicated by S. Hunter Christie, Esq. page 1 
II. Researches on the Decomposition and Disintegration of Phosphatic V esical Calculi, 
and on the Introduction of Chemical Decomponents into the Living Bladder. 
By S. Elliott Hoskins, M.D. Communicated by P. M. Roget, M.D., Sec. 
R.S 7 
III. Experimental Researches in Electricity. — Eighteenth Series. By Michael 
Faraday, Esq., D.C.L., F.R.S., Fullerian Prof. Chem. Royal Institution, Corr. 
Mernb. Royal and Imp. Acadd. of Sciences, Paris, Petersburgh, Florence, 
Copenhagen, Berlin, Gottingen, Modena, Stockholm, Sfc. Sfc 17 
IV. Spermatozoa observed within the Mammiferous Ovum. By Martin Barry, M.D., 
F.R.SS. L. and E 33 
V. Observations on certain cases of Elliptic Polarization of Light by Reflexion. By 
theR.ev. Baden Powell, M.A., F.R.S., F.G.S., F.R.A.S., Savilian Professor of 
Geometry in the University of Oxford 35 
VI. On the Laws of Individual Tides at Southampton and at Ipswich. By G. B. Airy, 
Esq., M.A., F.R.S., Astronomer Royal 45 
VII. Tide Observations at Otaheite, or Tahiti. By Captain Sir E. Belcher, R.N. 
Communicated by Captain Beaufort, R.N., F.R.S., fyc 55 
