376 Proceedings of the Royal Fhysical Society. 



SESSION CIX. 



JVednesday, IWi November 1879. — Dr R. H. Traquair, President, 

 in the Chair. 

 The following gentlemen were elected Ordinary Fellows of the Society : 

 D'Arcy W. Thompson ; W. Abbott Herdman ; and D. Noel Paton. 



An Opening Address was delivered by Dr Traquair, the retiring President, 

 on "The History of Scottish Fossil Ichthyology." 



Wednesday, 17th December 1879. — Professor Duns, President, in the Chair. 

 The following Office-Bearers were elected : 



Presidents— Trohssov J. Duns, D.D. ; Robert Etheridge, jun., F.G.S. ; 

 Professor Archibald Geikie, F.R.S. 

 Secretary — PtOBERT Gray. Assistant Secretary — John Gibson. 



Treasurer — Charles Prentice, C.A. 

 Librarian — Rev. J. Kennedy, M.A., B.D. 

 Councillors — Thomas Whyte, S.S.C. ; James Anderson; John Murray; 

 William Ferguson ; Andrew Taylor ; Principal Williams ; J. F. King ; 

 Alexander Galletly ; George Leslie ; A. B. Herbert ; R. H. Traquair. 

 The following gentlemen were elected Ordinary Fellows of the Society : 

 D. J. Balfour Kirke ; Rufus D. Pullar ; Henry Coates ; Earnest Ady. 

 The following communications were read : 



1. "On the Occurrence of the Poraarine Skua {Lestris pomarinus) in the East 



of Scotland in the Autumn of the present Year." (Specimens were 

 exhibited. ) By Dr R. H. Traquair. 



2. "On the Occurrence of the Greater Shearwater {Pujffinus major) at North 



Berwick." (Specimen exhibited.) By Dr R. H. Traquair. 



3. "On the Algse of the Firth of Forth." By G. W. M. Traill. Com- 



municated by Professor Duns. (Specimens new to the locality were 

 exhibited. ) 



4. "On the Distribution of the Goosander {Mergus merganser) in Scotland 



during the Breeding Season. " By J. H. Buchanan. 



5. " Obituary Notice of the late Dr M 'Bain. " By David Grieve. 



Wednesday, 'list January 1880. — Dr Traquair in the Chair. 

 The following gentlemen were elected Ordinary Fellows of the Society : 

 Thomas Bond Sprague, M.A. ; William Drummond, S.S.C. ; James Druni- 

 mond, C.A. 



The following communications were read : 

 1. Mr Edward Sang demonstrated experimentally the contraction of water 

 from the freezing point to its maximum density, and the expansion 

 thereafter. 

 This experiment was exhibited not as containing anything novel, but only 

 as showing in a very striking way the peculiar law according to which the 

 density of water changes with variations in temperature. 



A number of variously coloured closed glass balls, adjusted to different 



