11 CONTENTS. 



Page 



XI. Observations on the Presence of the Waters of the Gulf-Stream on the 

 Coasts of Europe, in January 1822. By Edward Sabine, Esq. F. R. S. 



F. L. S. <!*c. &c ----- - 270 



XII. On the Depression of the Horizon of the Sea over the Gulf-Stream. By 

 Edward Sabine, Esq. F. R. S. F. L. S. &c. &c. - - 274 



XIII. On the Effects of Heat and Motion. In a Letter to Dr Brewster 

 from M. Seguin, aim .,..-- 276 



XIV. Observations on the apparent Distances and Positions of 389 Double and 

 Triple Stars. By J. F. W. Herschel, Esq. Sec. R. S. Lond. and 

 F.R. S. Edin., and James South, Esq. F. R. S. Lond. & Edin. 281 



XV. On some Remarkable Affections of the Retina, as exhibited in its insen- 

 sibility to indirect Impressions, and to the Impressions of attenuated Light. 



By David Brewster, LL. D. F. R. S. Lond., and Sec. R. S. Edin. 288 



XVI. On the Action of Poisons on the Vegetable Kingdom. By Mr F. Mar- 

 cet, 2!)3 



XVII. On Two Newly determined Species of the Genus Gypsum-haloide of 

 the System of Mohs. By William Haidinger, Esq. F. R. S. E. 

 Communicated by the Author, - - - 302 



XVIII. On the Composition of the Minerals described in the preceding Paper. 

 By Edward Turner, M. D. F. R. S. E. &c. Lecturer on Chemistry, 

 and Fellow of the Royal College of Physicians, Edinburgh. Communicat- 

 ed by the Author, - ..... 300 



XIX. On the Chemical Characters of Zinc Ores, examined in the manner of 

 Berzelius, by means of the Blow-Pipe, by M. Nils Nordenskiold of 

 Abo, 310 



XX. Account of a Meteorological Phenomenon which was observed at the 

 Summit of Ben-Nevis on the 27th June last. By the Rev Mr John 

 Macvicar, Dundee. In a Letter to Dr Brewster, - - 312 



XXI. Description of Edingtonite, a New Mineral Species. By William 

 Haidinger, Esq. F. R..S. E. With an Analysis by Edward Turner, 

 M. D. F. R. S. E. &c. Lecturer on Chemistry, and Fellow of the Royal 

 College of Physicians, Edinburgh. Communicated by the Author, 31(i 



XXII. Description of a New Hygrometer, depending on the Affinity of Acids 



for Water. By Professor Aug. de la Rive, - - 320 



XXIII. On the Locality of Acmite. By N. B. Moller, Esq. of l'orsgrund, 

 Norway, - - - ... 32C 



XXIV. Account of Two newly-discovered Mineral Species. By Professor 



J. J. Berzelius, M. D. F. R. S. Lond. and Edin., &c. &c. - 327 



XXV. On some new Localities of rare Minerals. By Professor J. J. Ber- 

 zelius, M. D. F. R. S. Lond. and Edin., &c. &c. - - 332 



XXVI. ZOOLOGICAL COLLECTIONS, - - - 334 



1. Chlamyphorus truncatus, ib. 



2. New and gigantic species of the genus Cephalopterus, of Dumeril, 337 



3. Two new Genera of Reptiles proposed, ... 339 



4. Bilobitcs, - - - - - - ib. 



XXV II. HISTORY OF MECHANICAL INVENTIONS AND PRO- 



CESSES IN THE USEFUL ARTS, - - 340 



1. Method of giving the Epicycloidal Form to the Teeth of Wheels. By 

 PETER LecouNT, Esq. Midshipman, It. N. in a Letter to the Editor, ib. 



