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 Naturæ 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. GUILLEMIN,
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,
338
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. WÖHLER, 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