ii CONTENTS. 



Art. IX. Observations on the Fluids contained in Crystal- 

 lized Minerals. By William Nicol, Esq. Lec- 

 turer on Natural Philosophy. Communicated by 

 the Author, - - . , 94 



X. On covering the Roofs of Houses with Plates of Iron. 



By M. E. Carter. In a Letter to the Editor, 97 



XI. Notice regarding some extraordinary Lusus Naturae 

 in the East Indies. Communicated by Lieute- 

 nant James Edward Alexander, l6th Lancers, 

 M.R.A.S. Cor. Mem. S.A.E. &c. With a Plate, 98 

 XII. On the Fires that take place in Collieries ; and par- 

 ticularly on the Recent Fires in the Whitehill and 

 Polton Collieries, in Mid-Lothian ; and South 

 Sauchie Colliery, in Clackmannanshire. By Ro- 

 bert Bald, Esq. Mining Engineer, F. R. S. E. 

 M. W. S. &c. Communicated by the Author. 

 With Plates, - - - - 101 



XIII. Abstract of a Memoir read before the Wernerian So- 

 ciety, giving an account of Experiments directed 

 to ascertain the Principles of Attraction and Re- 

 pulsion in the Lunar Rays, &c. ; a Description of 

 several Varieties of the Instruments constructed 

 for that purpose ; and some Applications of the 

 Observations made, as illustrative' of other sub- 

 jects. By Mark Watt, Esq. M. W. S. &c. 122 



XI Vv On the History and Constitution of Benefit or Friend- 

 ly Societies. By Mr W. Eraser, Edinburgh. 

 1 Concluded from former Number, p. 313. - 129 



XV. On the Velocity of Sound. In a Letter from G. Von 

 Moll, F.R.S. Professor of Natural Philosophy in 

 the University of Utrecht, to Professor Jameson, I54t 



XVI. Some Remarks on the Bushmen of Orange River. 

 By Louis Leslie, Esq. Assistant Surgeon, 45th 

 Regiment. Communicated by Sir James M'Gri- 

 GOR, Director-General of the Army Medical Board, 157 

 XVII. Observations on the Structure of the Heart of Ani- 

 mals of the genus Rana. By John Daw, M. D. 

 F. R.S. Communicated by Sir James M'Grigor, 

 Director-General of the Army Medical Board, I60 

 XVIII. Notice in regard to the Jaculator Fish of Java, or 

 Chaetodon rostratum, Lin. By James Mitchell, 

 Esq. Surgeon, R. N. Communicated by the Au- 

 thor, - - - - - 162 



