APPENDIX. — KEITH, MAKDOUGALL-BRISBANE, AND NEILL PRIZES. 691 



20th Biennial Period, 1865-67. — Professor C. Piazzi Smyth, for his paper "on Recent 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 Fixed Point," published in the Transactions of 

 the Society. 



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



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

 Society. 



23rd Biennial Period, 1871-73, — Professor P. G. Tait for his paper entitled "First Approximation 



to a Thermo-electric Diagram," published in the Transactions 

 of the Society. 



24th Biennial Period, 1873-75. — Professor Crum Brown, for his Researches "on the sense of Rota- 

 tion, and on the Anatomical Relations of the Semicircular 

 Canals of the Internal Ear." 



25th Biennial Period, 1875-77. — Professor M. Forster Heddle, for his papers "on the Rhom- 



bohedral Carbonates," and " on the Felspars of Scotland," 

 published in the Transactions of the Society. 



26th Biennial Period, 1877-79. — Professor H. C. Fleeming Jenkin, for his paper "on the Appli- 

 cation of Graphic Methods to the Determination of the Effi- 

 ciency of Machinery," published in the Transactions of the 

 Society; Part IT. having appeared in the volume for 1877—78. 



27th Biennial Period, 1879-81. — Professor George Chrystal, for his paper "on the Differential 



Telephone," published in the Transactions of the Society. 



28th Biennial Period, 1881-83. — Thomas Muir, Esq., LL.D., for his "Researches into the Theory 



of Determinants and Continued Fractions," published in the 

 Proceedings of the Society. 



29th Biennial Period, 1883-85. — Johm Aitken, Esq., for his paper "on the Formation of Small 



Clear Spaces in Dusty Air," and for previous papers on 

 Atmospheric Phenomena, 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. 



2nd 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. 



3rd 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. 

 8th Biennial Period, 1872-74. — Professor Lister, for his paper "on the Germ Theory of Putre- 

 faction and the Fermentive Changes," communicated to the 

 Society, 7th April 1873. 



