CONTENTS. vii 



XV. On a New Species of Coloured Fringes, produced 

 by tht Reflection of Light between Two Plates of 

 parallel Glass of equal thickness. By David 

 Brewster, LL. D. F. R. S. Edin. & F. A. S. E. 435 



XVI. An Analysis of the Mineral Waters of Cromlix^ 

 near Dunblane, and of Pitcaithly ; with general 

 Observations on the Analysis of Mineral Waters, 

 and the ComposHion of Bath Water and some 

 others. By John Murray, M. D. F. R. S. Edin. • 445 

 XVII. Biographical Account of the late John Robison, 

 LL. D. F. R. S. Edin. and Professor of Natural 

 Philosophy in the University of Edinburgh. By 

 John Playfair, F. R. S. L. & E. &c. 495 



•Appendix, containing Lists of the Office-bearers and 



Members elected since November 1812, - 541 



