ii CONTENTS. 



Art. X. On the Structure and Characters of the Octopus ven- 

 tricosus, Gr. (Sepia octopodia^ Pent), a rare spe- 

 cies of Octopus from the Firth of Forth. By R. E. 

 Grant, M. D. F. R. S. E. &c. Fellow of the Royal 

 College of Physicians of Edinburgh, Honorary 

 Member of the Northern Institution, &c. Com- 

 municated by the Author, - - 309 

 XI. Meteorological Observations made in Jamaica by the 

 late John Lindsay, Esq. Surgeon, Jamaica. Com- 

 municated by W. C. Trevelyan, Esq. M. W.S. &c. 317 

 XII. A Description of the genus Malesherbia of the Flora 

 Peruviana; with Remarks on its Affinities. By 

 Mr David Don, Libr. L. S. ; Member of the Impe- 

 rial Academy Natura? Curiosorum, of the Werne- 

 rian Nat. Hist. Society, &c. - - 320 



XIII. Account of a Gelatinous Quartz or Siliceous Sinter, 



which forms the basis of varieties of Old Red Sand- 

 stone. By M. T. Gutllemin, - - 324 



XIV. Experiments to compare the specific Heat of Air un- 



der a constant volume, with its specific Heat under 

 a constant pressure. By Mr Henry Meikle. Com- 

 municated by the Author, - - 328 

 XV. On the Detection of Arsenic in cases of Poisoning. 



By J. L. Berzelius, - - _ $$8 



XVI. On a Chemical Composition of Zinkenite and Jame- 

 sonite. By H. Rose, Member of the Royal Aca- 

 demy of Berlin. And Description and Analysis of 

 Pyrochlore, a new Mineral. By F. Wohler, 341 



XVII. The Law of the Preservation of Species, illustrated 

 by the Phenomena of the seed of the Stipa pennata. 

 By Mr John Macvicar, Lecturer on Natural His- 

 tory in St Andrew's, (With a Plate.) Communi- 

 cated by the Author, _ - . 343 

 XVIII. Account of the Observations and Experiments made 

 on the Diurnal Variation and Intensity of the Mag- 

 netic Needle, by Captain Parry, Lieutenant Foster, 

 and Lieutenant Ross, in Captain Parry's Third 

 Voyage ; with Remarks and Illustrations. By Pe- 

 ter Barlow, F. R. S. Mem. of the Imperial Aca- 

 demy of St Petersburgh, &c. (With a Plate.) 

 Communicated by the Author, - - 347 

 XIX. On the Use of a Simple Syphon as a Hydrometer. By 



Mr H. Meikle. Communicated by the Author, 366 



