I 
Id 12, 
Sc-My,i£ ■ ■ 
CONTENTS 
OF 
No. XXIII. 
Page 
Art. I. On Crystallisation. By H. J. Brooke, Esq. F. R.S. 1 
II. Observations on Radiant Heat. By William Ritchie, 
A. M. Rector of the Academy at Tain, - 15 
^ III. Account of the Erection of the Bell Rock Lighthouse. 
With a Plate, - - - 18 
IV. On the Principles and Practice of Warming and Ven- 
/ tilating Buildings. By Thomas Tredgold, Civil 
Engineer, and Honorary Member of the Institution 
of Civil Engineers, - - - 38 
V. On certain Antediluvian Plants, susceptible of being 
illustrated by means of .species now living within 
the Tropics. By Dr C. F. P. De Martius, Mem- 
ber of the Royal Botanical Society of Ratisbon, 
VI. Short Account of the Forest Trees and Timber Trade 
of the Interior of Russia. By William Howison, 
M. D. Lecturer on Materia Medica, and Theory and 
Practice of Medicine, Edinburgh, - 56 
VII. On the modes of Notation of Weiss, Mohs, and Haiiy. 
By A. Levy, Esq. of the Academy of Paris, - 70 
VIII. Description of Eudalite. By A. Levy, Esq. Member 
of the Academy of Paris, - - 81 
IX. On the Cochlea of the Internal Ear of Birds. By Dr 
G. R. T REV iranus. Professor of Medicine, Bremen. 
Communicated by the Author, - - S2 
X. On the Aurora Borealis and Polar Fogs. By Profes- 
sor Hansteen, - - - 88 
