CONTENTS. 
XXVI. On the apparent magnetism of Metallic Titanium. By 
William Hyde Wollaston, M. D. V. P. R. S. p. 400 
XXVII. An account of the effect of Mercurial Vapours on the 
Crew of His Majesty’s Ship Triumph, in the year 1810. By 
William Burnett, M. D. one of the Medical Commissioners 
of the Navy , formerly Physician and Inspector of Hospitals to 
the Mediterranean Fleet. Communicated by Matthew Baillie, 
M.D.F.R.S. 402 
XXVIII. On the Astronomical Refractions. By J. Ivory, A. M. 
F. R. S. p. 409 
XXIX. Observations on Air found in the Pleura, in a case of 
Pneumato-thorax ; with experiments on the absorption of different 
kinds of air introduced into the pleura . By John Davy, 
M. D. F. R. S. p. 4 96 
XXX. On Bitumen in Stones . By the Right Honourable 
George Knox, F. R. S. p. 517 
XXXI. On certain changes which appear to have taken place in 
the positions of some of the principal fixed stars. By John 
Pond, Astronomer Royal, F. R. S. p. 529 
Presents received by the Royal Society from November Jth, 1822, 
to June 19, 1823, with the Names of the Honors. p. 541 
Index p. 549 
