— 
CONTENTS. 
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., 
XVIII. On some remarkable Marine Invertebrata new to the British Seas. 
By Epwarp Forses, F.R.S., F.L.S., Professor of Botany, King’s 
College, London ; and J. Goopsir, F.R.SS.L. & E., Professor of 
Anatomy in the University of Edinburgh. (With Two Plates.) 

PART III. 
XIX. On the Total Intensity of Interfering Light. By Protessor StoxEs, 
XX. Some Observations on the Charr (Salmo umbla), relating chiefly to tts 
Generation aud Early Life. By Joun Davy, M.D., F.R.SS. 
L. & E., Inspector-General of Army Hospitals, : 
XXI. On the Total Eclipse of the Sun, on July 28, 1851, observed at Gote- 
borg ; with a Description of anew Position Micrometer. By Wi1- 
LIAM Swan, F.R.S.E. (With a Plate.) 
XXII. Researches on some of the Crystalline’Constituents of Opium. By 
Tuomas ANDERSON, M.D., F.R.S.E., ; : : 
XXII. On a Necessary Correction to the Observed Height of the Barometer 
depending upon the Force of the Wind. By Captain Henry Jamss, 
R.E., F.R.S., M.R.LA., F.G.S., &c. : : 
XXIV. Defence of the Doctrine of Vital Afinity. By Wit~1Am PULTENEY 
Auxtson, M.D., &c. &c., Professor of the Practice of Medicine in 
the University of Edinburgh, 
XXV. On Meconic Acid and some of its Derivatives. By Mr Henry How, 
Assistant to Dr ANDERSON. Communicated’by Dr T. ANDER- 
SON, 
XXXVI. Notice of an Antique Marble Bust. By ANDREW CovENTRY, Esq., 
. 299 
307 
317 
335 
347 
377 
385 
401 
417 
