of Edinburgh, Session 1864-65. 381 
Die Fossilen Mollusken des Tertiasr-Beckens von Wien. Yon Dr 
M. Hornes. Band II. 5, 6. 4to. Wien, 1865. — From the 
Author. 
Monthly Notices of the Eoyal Astronomical Society, Yol. XXY. 
No. 3. 8vo. London, 1865. — From the Society. 
Letter from John Davy, M.D., F.K.S., addressed to the editors of 
the Philosophical Magazine, in reply to a certain charge 
made by Charles Babbage, Esq., F.K.S., against the late Sir 
Humphry Davy, when President of the Boyal Society. 8vo. 
— From Dr Davy. 
Proceedings of the Natural History Society of Dublin for 1863-61. 
Yol. lY. Part II. 8vo. Dublin, 1865. — From the Society. 
The American Journal of Science and Arts, Yol. XXXIX. No. 115. 
8vo. New Haven, 1865. — From the Editors. 
The Quarterly Journal of the Greological Society, Yol. XXI. Part I. 
8vo. London, 1865. — From the Society. 
The Journal of the Linnean Society, Yol. YIII. No. 32, Botany. 
8 VO. London, 1865. — From the Society. 
Beale Istituto Lombardo di Scienze e Lettere — Kendiconti — Classe 
di Scienze Matematiche e Natural!. Yol. I. Fasc. 7, 8. Classe 
di Lettere e Scienze Morale e Politiche. Yol. I. Fasc. 7. 8vo. 
Milano, 1861. — From the Institute. 
Solenni Adunanze del Beale Istituto Lombardo di Scienze e 
Lettere, Adunanza del 7 Agosto 1861. 8vo. Milano, 1861. 
— From the Institute. 
Journal of the Chemical Society, January 1865. 8vo. London, 
1865. — From the Society. 
Monday, Qth March 1865. 
Sir DAVID BEEWSTEE, President, in the Chair. 
1. On the World as a Dynamical and Immaterial World. 
By Eobert S. Wyld, Edinburgh. 
What is matter? has been the question of philosophy from the 
earliest times. The author of this paper referred to the specula- 
