268 Proceedings of the Royal Society of Edinburgh. [Sess. 
4th Triennial Period, 1893-96.— John Aitken, Esq., for his brilliant Investigations in 
Physics, especially in connection with the Formation and Condensation of Aqueous Vapour. 
1st Quadrennial Period, 1896-1900. — Dr T. D. Anderson, for his discoveries of New and 
Variable Stars. 
2nd Quadrennial Period, 1900-04.— Sir James Dewar, LL.D., D.C.L., F.R.S., etc., for his 
researches on the Liquefaction of Gases, extending over the last quarter of a century, and 
on the Chemical and Physical Properties of Substances at Low Temperatures : his earliest 
papers being published in the Transactions and Proceedings of the Society. 
3rd Quadrennial Period, 1904-08. — Professor George Chrystal, M.A., LL.D., for a series of 
papers on “Seiches,” including “ The Hydrodynamical Theory and Experimental Investiga- 
tions of the Seiche Phenomena of Certain Scottish Lakes.” 
4th Quadrennial Period, 1908-12. — Professor J. Norman Collie, Ph.D., F.R.S. , for his 
distinguished contributions to Chemistry, Organic and Inorganic, during twenty-seven 
years, including his work upon Neon and other rare gases. Professor Collie’s early papers 
were contributed to the Transactions of the Society. 
5th Quadrennial Period, 1912-16. — Sir Thos. Muir, C.M.G., LL.D., F.R.S., for his series 
of Memoirs upon “ The Theory and History of Determinants and Allied Forms,” published 
in the Transactions and Proceedings of the Society between the years 1872 and 1915. 
