[ Vi ] 
XXIV. On the Illumination of Light-houses. By Lieut. Thomas Drummond 
of the Royal Engineers. Communicated by Lieut. Colonel Colby of the 
Royal Engineers , F.R.S. page 383 
XXV. On the electro-magnetic properties of metalliferous veins in the mines of 
Cornwall. By Robert Were Fox. Communicated by the President. 399 
XXVI. Sequel to a paper on the tendency to Calculous Diseases, and on the 
Concretions to which such diseases give rise. By John Yelloly, M.D. 
F.R.S 415 
Index 429 
Appendix. 
Presents received by the Royal Society, from Nov. 19 th 1829 to June 17 th 1830. 
Meteorological Journal, hept at the Apartments of the Royal Society, by order of 
the President and Council. 
ERRATA in Part I. 
Page 74, dele the last paragraph but one. 
142, in the second formula, line 4th, for <p, read 1. 
Part II. 
Page 260, last line, for fire read ice. 
282, line 8, for heated read luted. 
