of Edinburgh, Session 1863-64. 175 
over de Danske Diatomeer af Dr Phil. P. A. C. Heiberg. 
8vo . — -From the Author. 
Monthly Notices of the Astronomical Society. Vol. XXIV. No. 2. 
8vo.— AVom the Society. 
The Journal of the Chemical Society. December 1863, January 
1864 . — From the Society. 
Leeds Philosophical and Literary Society. Annual Eeport for 
1862-3. ^wo.—From the Society. 
Monthly Eeturn of the Births, Marriages, and Deaths registered in 
the Eight Principal Towns of Scotland. December 1863. 
8 VO. — From the Registrar-General. 
The Eolations of Science to Modern Civilisation. By Professor H, 
Hennessy. 8vo.— AVom the Author. 
Jahreshericht iiher die Fortsohritte der Chemie, etc. Yon H. Kopp 
u. H. Will, fiir 1862. Erstes Heft. 8vo . — From the Authors. 
Proceedings of the Eoyal Horticultural Society. January 1864’ 
8 VO.-— From the Society. 
Essays on Digestion. By Dr J. Carson. 8vo.— From the Author. 
Memorie Botaniche. Presentate alia E. Accademia delle Scienzo 
Fisico-Matematiche, anno 1862. 4tio.—From the Society. 
Proceedings of the Eoyal Society, Vol. XIII. No. 59, 8vo.— * 
From the Society. 
Edinburgh Astronomical Observations. Vol. XII. 4to.— AVom 
the Royal Observatory ; forwarded by the Astronomer- Royal for 
Scotland. 
Monday, Ibth February 1864. 
Dr CHKISTISON, Vice-President, in the Chair, 
The following Communications were read :■ — - 
1. On the Influence of the Eefracting Force of Calcareous 
Spar on the Polarization, the Intensity, and the Colour of 
the Light which it Eeflects, By Sir David Brewster, K.H., 
F.E.S. 
In the Philosophical Transactions ” for 1819, the author had 
shown that the doubly refracting force of calcareous spar extended 
beyond the sphere of the reflecting force, producing a change io 
