CONTENTS. 
Page 
Arr. I. On the Geological Investigations and Writings of 
Baron Alexander Von Humboldt. By the late 
Professor FreprericK HorrMann of Berlin, 205 
II. On the Use of Chlorine as an Indication of the I- 
luminating Power of Coal Gas, and on the Com- 
parative Expense of Light derived from different 
sources. By Anprew Fryer, M.D., F.R.S.E., 
FR.S.S.A. Communicated by the Royal Scot- 
tish Society of Arts, ‘ . 
III. On the General Movements of Serpents. By M. 
Dumerit, : : : - 235 
IV. A General View of the Environs of Pekin. By M. 
Koyanxo, Major in the Corps of Engineers of 
Mines ; translated by Lieutenant-General Lord 
GreENock, F.R.S.E., from the Annuaire du Jour- 
nal des Mines de Russie, année 1838, Published 
at St Petersburg, 1840, : : 242 
V. On the Cultivation of the Sugar-Cane in Spain. 
By Tuomas Srewarr Trait, M.D., F.R.S.E. 
(Communicated by the Author.) Read before the 
Royal Society of Edinburgh, : . 256 
VI. Notice of Experiments regarding the Visibility of 
Lights in rapid Motion, made with a view to the 
Improvement of Lighthouses, and of some pecu- 
liarities in the impressions made by them on the 
Eye. By Aran Stevenson, LL.B., F.R.S.E., 
Civil Engineer. Communicated by the Author, 270 
221 
