viii THE KEITH, MAKDOUGALL BRISBANE, AND NEILL PRIZES. 



15th Biennial Period, 1855-57. — Professor Boole, for his Memoir "on the Application of the Theory 



of Probabilities to Question of the Combination of Testimonies 

 and Judgments," published in the Transactions of the Society. 



16th Biennial Period, 1857-59. — Not awarded. 



17th Biennial Period, 1859-61. — John Allan Broun, Esq., F.R.S., Director of the Trevandrum 



Observatory, for his papers "on the Horizontal Eorce of the 

 Earth's Magnetism, on the Correction of the Bifilar Magnet- 

 ometer, and on Terrestrial Magnetism generally," published in 

 the Transactions of the Society. 



18th Biennial Period, 1861-63. — Professor William Thomson, of the University of Glasgow, for his 



Communication " on some Kinematical and Dynamical 

 Theorems," published in the Transactions of the Society. 



19th Biennial Period, 1863-65. — Principal Eorbes, St Andrews, for bis " Experimental Inquiry into 



the Laws of Conduction of Heat in Iron Bars," published in 

 the Transactions of the Societj-. 



20th Biennial Period, 1865-67. — Professor C. Piazzi Smyth, for his paper "on Eecent Measures at 



the Great Pyramid," published in the Transactions of the 

 Society. 



21st Biennial Period, 1867 -69. — Professor P. G. Tait, for his paper "on the Rotation of a Rigid 



Body about a Eixed Point," published in the Transactions of 

 the Society. 



22d Biennial Period, 1869-71. — Professor Clerk Maxwell, for his paper "on Figures, Frames, 



and Diagrams of Forces," published in the Transactions of the 

 Society. 



II. MAKDOUGALL BRISBANE PRIZE. 



1st Biennial Period, 1859. — Sir Roderick Impey Murchison, on account of his Contributions to the 



Geology of Scotland. 



2d Biennial Period, 1860-62.— William Seller, M.D., F.R.C.P.E., for his "Memoir of the Life 



and Writings of Dr Robert Whytt," published in the Trans- 

 actions of the Society. 



3d Biennial Period, 1862-64. — John Denis Macdonald, Esq., R.N., F.R.S., Surgeon of H.M.S. 



" Icarus," for his paper "on the Representative Relationships 

 of the Fixed and Free Tunicata, regarded as two Sub-classes 

 of equivalent value; with some General Remarks on their 

 Morphology," published in the Transactions of the Society. 



4th Biennial Period, 1864-66. — Not awarded. 



5th Biennial Period, 1866-68. — Dr Alexander Crum Brown, and Dr Thomas Richard Fraser, for 



their conjoint paper " on the Connection between Chemical 

 Constitution and Physiological Action," published in the 

 Transactions of the Society. 



6th Biennial Period, 1868-70. — Not awarded. 



7th Biennial Period, 1870-72. — George James Allman, M.D., F.R.S., Emeritus Professor of Natural 



History, for his paper 'on the Homological Relations of 

 the Ccelenterata,' published in the Transactions, which forms 

 a leading chapter of his Monograph of Gymnoblastic or Tubu- 

 larian Hydroids — since published. 



