XIII. On Cystic Oxide , a new species of Urinary Calculus. 
By William Hyde Wollaston, M.D. Sec.R.S. p. 223 
XIV. Researches on the oxymuriatic Acid , its Nature and Combi- 
nations ; and on the Elements of the muriatic Acid. With some 
Experiments on Sulphur and Phosphorus , made in the Laboratory 
of the Royal Institution. By H. Davy, Esq. Sec. R.S. Prof. 
Chern.R.I. F.R.S.E. p. 231. 
XV. Observations upon Luminous Animals. By J. Macartney, 
Esq. Communicated by Everard Home, Esq. F.R.S. p. 238 
XVI. Observations and Experiments on Pus. By George 
Pearson, M.D. F.R.S. p. 294 
Presents received by the Royal Society, from November , 1 809, 
to July, 1810. p. 319 
Index . p. 325 
