CONTENTS. 



and floating ice of Baffin's Bay. — Causes of the progres- 

 sion of the Spitzbergen Glaciers. 

 Additional Note, ...... 295 



VII. Notice relative to Long's American Frame-Bridge. 

 By David Stevenson, Esq., Civil Engineer, 

 Edinburgh. Communicated by the Society of 

 Arts for Scotland, 297 



VIII. On the Tea-Plantations in India, . . . 301 



IX. On Spring and River Water, as connected with 



Health and the Arts, .... 307 



X. On an Erroneous Deduction drawn by the late Cap- 

 tain Henry Kater from his Experiment on 

 the Flexure of Thin Bars. By Edward Sang, 

 Esq., Actuary, Edinburgh, M.S. A. Communi- 

 cated by the Society of Arts for Scotland, . 321 



XI. On Trigonometrical Surveying and Levelling, and 

 on the Effects of a Supposed Local Attraction at 

 the Calton Hill. By William Galbraith, M.A., 

 M.S. A., Edinburgh; F.R.A.S., London. Com- 

 municated by the Society of Arts for Scotland, 326 



XII. Notice of a New Signal-Light for Railways. By 

 Alan Stevenson, LL.B. Civil Engineer, Edin- 

 burgh. Communicated by the Society of Arts for 

 Scotland, 347 



XIII. On the Forms assumed by Uncrystallized Mineral 

 Substances, such as the Ocellated Stones of Den- 

 dera in Upper Egypt, the stones of Imatra, &c. 

 By M. Ehrenberg, 353 



XIV. Speculations as to the Primary Source of the Car- 

 bon and Nitrogen present in Plants and Animals. 

 By Charlzs Daubent, M.D., F.R.S., &c. &c, 360 



XV. On the Natural History and Anatomy of Thalasse- 

 ma and Echiurus. By Edward Forbes, Esq. 

 and John Goodsir, Esq. Members of the Wer- 

 nerian Natural History Society. Communicated 

 by the Authors 369 



XVI. On the Employment of the Safety-Lamp in the 

 Coal-Mines of Germany. By Professor Gustat 



