viii 



March 17, 1870. Page 

 On the Law which regulates the Relative Magnitude of the Areas of the 

 four Orifices of the Heart. By Herbert Davies, M.D., F.R.C.P., Senior 

 Physician to the London Hospital, and formerly Fellow of Queens' Col- 

 lege, Cambridge 265 



On the Estimation of Ammonia in Atmospheric Air. By Horace T. 

 Brown, Esq 286 



March 24, 1870. 



On the Madreporaria dredged up in the Expedition of H.M.S. ' Porcupine.' 

 By P. Martin Duncan, M.B. Lond., F.R.S., Sec. Geol. Soc, Professor of 

 Geology in King's College, London 289 



March 31, 1870. 



On the Relation between the Sun's Altitude and the Chemical Intensity of 

 Total Daylight in a Cloudless Sky. By Henry E. Roscoe, F.R.S., and 

 T. E. Thorpe, Ph.D 301 



On the Acids contained in Crab-oil. By William J. Wonfor, Student in the 

 Laboratory of the Government School of Science, Dublin 304 



List of Presents 307 



No. 119.— April 7, 1870. 



On Supra-annual Cycles of Temperature in the Earth's Surface-crust. By 

 Prof. C. Piazzi Smyth, F.R.S 311 



On the Constituent Minerals of the Granites of Scotland, as compared with 

 those of Donegal. Bv the Rev. Samuel Haughton, F.R.S., M.D. Dubl., 

 D.C.L. Oxon., FelWof Trinity College, Dublin 312 



Researches on Vanadium. — Part III. Preliminary Notice. Bv Henry E. 

 Roscoe, B.A., F.R.S 316 



April 28, 1870. 



On the Organs of Vision in the Common Mole. By Robert James Lee, M.D. 322 



On an Aplanatic Searcher, and its Effects in improving High-Power De- 

 finition in the Microscope. By G. W. Rovston-Pigott, M.A., M.D. 

 Cantab., M.R.C.P., F.R.A.S., FlC.P.S., formerly Fellow of St. Peter's 

 College, Cambridge 327 



On a Cause of Error in Electroscopic Experiments. By Sir Charles Wheat- 

 stone, F.R.S 330 



May 5, 1870. 



The Bakerian Lecture. By John W. Dawson, LL.D., F.R.S., &c, Principal 

 and Vice-Chancellor of M'Gill College, Montreal, " On the Pre-Carboni- 

 ferous Floras of North-Eastern America, with especial reference to that 

 of the Erian (Devonian) Period" 333 



List of Presents 335 



No. 120.— May 12, 1870. 



The Croonian Lecture. By Augustus Waller, M.D., F.R.S., of Geneva, 

 "On the Results of the'Methcd introduced by the Author of investi- 

 gating the Nervous System, more especially as applied to the elucidation 

 of the Functions of the Pneumcgastiic and Sympathetic Nerves" 339 



