CONTENTS. 
XX. An improved method of dividing Astronomical Circles and 
other Instruments, By Capt. Henry Kater. Communicated 
by Thomas Young, M. D. For. Sec, R. S, p. 419 
XXI. Results of some recent Experiments on the Properties im- 
pressed upon Light by the Action of Glass raised to different 
Temperatures, and cooled under different Circumstances . By 
David Brewster, LL. D. F. R. S, Edin, and F, A. S. E. in a 
Letter to the Right Hon, Sir Joseph Banks, Bart, K. B, 
P.R.S, &c. &c, &c, p. 436 
XXII. Consideration of various Points of Analysis. By John 
F. W. Herschel, £5^. F. R. S. p. 440 
XXIII. Observations on the Functions of the Brain. By Sir 
Everard Home, Bart. F. R. S, p. 469 
XXIV. Further Experiments and Observations on Iodine. By 
Sir H. Davy, LL. D. F. R. S. V. P. R. I, p, 487 
XXV. Observations respecting the natural production of Saltpetre 
on the walls of subterraneous and other Buildings. By John 
Kidd, M.D. Professor of Chemistry at Oxford. Communicated 
by William Hyde Wollaston, M. D. Sec. R. S. p. 508 
XXVI. On the Nature of the Salts termed triple Prussiates, and 
on Acids formed by the union ofcertam Bodies with the Elements 
of the Prussic Acid. By Robert Porrett, /««. Esq. Commu-^ 
nicated by William Hyde Wollaston, M. D. Sec. R. S. 
P- 527 
XXVII. Some Experiments on the Combustion of the Diamond 
and other carbonaceous Substances. By Sir Humphry Davy, 
LL. D. F. R. S. V. P. R. I. p. 557 
XXVIII. Some Account of the fossil Remains of an Animal more 
nearly allied to Fishes than any of the other Classes of Animals. 
By Sir Everard Home, Bart. F. R. S. p. 571 
