ii CONTENTS. 
Art. V. Observations on the Production of Electricity by Con- 
tact. By C. G. Gmelin, Professor of Chemistry in 
the University of Tubingen. Communicated by the 
Author, - • « 32 
VI. On the Coral Islands of the Pacific Ocean. By Dr 
A. YON Chamisso, - - - 37 
VII. Observations on the Final Report of the Commissioners 
qf Weights and* Measures. By the Rev. George 
Skene Keith, D. D. - - 41 
VIII. Remarks on Azalea, Rhododendron, Ledum, and Leio- 
phyllum; with Characters of these four Genera. 
By Mr David Don, Curator of the Lambertian Her- 
barium, - - « - 47 
I^. On the Geographical distribution qf Insects. By 
M. Latreille. (Concluded from Vol. V. p. 378.) 51 
X. Observations on the Countries of Congo and Loango, 
as in 1790 . By Mr Maxwell, Author of Letters to 
Mungo Park, &c. (Continued from Vol. V. p. 275.) 62 
XI. Observations on the Difference of Level of the East 
and West Seas. By John Robison, Esq. F. R. S. E. 
In a Letter to Dr Brewster, - - 69 
XII. A Monograph of the Genus Erinepm. By Robert 
Kaye Greville, Esq. F. R. S. E., M. W. S. &c. 
Communicated by the Author, . - - 71 
XIII. Account of Electro-Magnetic Experiments made by 
MM. Van Beek, Prof. Van Rees of Liege, and Prof. 
Moll of Utrecht. In a Letter to Dr Brewster, 83 
XlVi Notice respecting Dr Wallich’s Journey in Nepaul ; 
being an Extract of a Letter from Dr Wallich, Su- 
perintendant of the Botanical Garden near Calcutta, 
to Dr Francis Hamilton; dated Nepaul, 28th 
March 1821, - - - 86 
XV. Notice of Mineralogical Journeys, and of a Mineralo- 
gical System, by the late Rev. Dr John Walker, 
Professor of Natural History in the University of 
Edinburgh, - - - 88 
XVI. Observations on Water-Spouts. By the Honourable 
Captain Napier, R. N. F. R. S. E. In a Letter to 
Dr Brewster, - - - 95 
XVII. Observations on Vision through Coloured Glasses, and 
on their application to Telescopes, and to Microscopes 
of great magnitude. By David Brewster, LL. D. 
F. R. S. L. &. Sec. R. S. Edim - - 102 
