﻿CONTENTS. 
  Vll 
  

  

  PAGE 
  

  

  XVII. 
  On 
  the 
  Weight 
  of 
  Aqueous 
  Vapour 
  which 
  is 
  condensed 
  on 
  a 
  Cold 
  

   Surface, 
  under 
  given 
  conditions. 
  By 
  James 
  Dalmahoy, 
  Esq., 
  

   F.R.S.E., 
  . 
  . 
  . 
  .>'.. 
  • 
  • 
  299 
  

  

  XVIII. 
  On 
  some 
  remarkable 
  Marine 
  Invertebrata 
  new 
  to 
  the 
  British 
  Seas. 
  

   By 
  Edwaed 
  Foebes, 
  F.R.S., 
  F.L.S., 
  Professor 
  of 
  Botany, 
  King's 
  

   College, 
  London; 
  and 
  J. 
  Goodsie, 
  F.R.SS.L. 
  & 
  E., 
  Professor 
  of 
  

   Anatomy 
  in 
  the 
  University 
  of 
  Edinburgh. 
  (With 
  Two 
  Plates.) 
  307 
  

  

  PART 
  III. 
  

  

  XIX. 
  On 
  the 
  Total 
  Intensity 
  of 
  Interfering 
  Light. 
  By 
  Professor 
  Stokes, 
  317 
  

  

  XX. 
  Some 
  Observations 
  on 
  the 
  Gharr 
  (Salmo 
  umbla), 
  relating 
  chiefly 
  to 
  its 
  

   Generation 
  aud 
  Early 
  Life. 
  By 
  John 
  Davy, 
  M.D., 
  F.R.SS. 
  

   L. 
  &E., 
  Inspector-General 
  of 
  Army 
  Hospitals, 
  . 
  . 
  326 
  

  

  XXI. 
  On 
  the 
  Total 
  Eclipse 
  of 
  the 
  Sun, 
  on 
  July 
  28, 
  1851, 
  observed 
  at 
  Gbte- 
  

   borg 
  ; 
  with 
  a 
  Description 
  of 
  anew 
  Position 
  Micrometer. 
  By 
  Wil- 
  

   liam 
  Swan, 
  F.R.S.E. 
  (With 
  a 
  Plate.) 
  . 
  . 
  .335 
  

  

  XXII. 
  Researches 
  on 
  some 
  of 
  the 
  Crystalline 
  "Constituents 
  of 
  Opium. 
  By 
  

  

  Thomas 
  Andeeson, 
  M.D., 
  F.R.S.E., 
  . 
  . 
  . 
  347 
  

  

  XXIII. 
  On 
  a 
  Necessary 
  Correction 
  to 
  the 
  Observed 
  Height 
  of 
  the 
  Barometer 
  

  

  depending 
  upon 
  the 
  Force 
  of 
  the 
  Wind. 
  By 
  Captain 
  Heney 
  James, 
  

   R.E., 
  F.R.S., 
  M.R.I.A., 
  F.G.S., 
  &c. 
  . 
  . 
  . 
  . 
  377 
  

  

  XXIV. 
  Defence 
  of 
  the 
  Doctrine 
  of 
  Vital 
  Affinity. 
  By 
  William 
  Pulteney 
  

  

  Alison, 
  M.D., 
  &c. 
  &c, 
  Professor 
  of 
  the 
  Practice 
  of 
  Medicine 
  in 
  

  

  the 
  University 
  of 
  Edinburgh, 
  ..... 
  385 
  

  

  XXV. 
  On 
  Meconic 
  Acid 
  and 
  some 
  of 
  its 
  Derivatives. 
  By 
  Mr 
  Heney 
  How, 
  

   Assistant 
  to 
  Dr 
  Andeeson. 
  Communicated^ 
  by 
  Dr 
  T. 
  Andee- 
  

   son, 
  ........ 
  401 
  

  

  XX"V 
  I. 
  Notice 
  of 
  an 
  Antique 
  Marble 
  Bust. 
  By 
  Andeew 
  Coventey, 
  Esq., 
  417 
  

  

  