PROCEEDINGS 
OF THE 
ROYAL SOCIETY OF EDINBURGH. 
SESSION 1878-79. 
CONTENTS. 
PAGE 
Monday , 24 th November 1878. 
Election of Office-Bearers, . . . .1 
Monday , 2 d December 1878. 
Opening Address by the President, Professor Kelland, . 2 
Monday , 1 6th December 1878. 
On the Action of Light on the Iris. By William Ackroyd, 
E.I.C;, &c. Communicated by Professor M‘Kendrick, 37 
On a New Variety of Ocular Spectrum. By John Aitken, 40 
On the Principles of the Logical Algebra ; with Applica- 
tions. Part I. By Alexander Macfarlane, M.A., 
D.Sc., 44 
Note on Ulodendron and Halonia. By D’Arcy Went- 
worth Thompson. Communicated by Sir Wyville 
Thomson, . . . . . . 44 
Monday , 6 th January 1879. 
Notes on some Experiments with the Telephone. By James 
Blyth, M.A., . . . . .45 
On the Measurement of Beknottedness. By Professor Tait, 48 
Preliminary Note on the Measurement of the Thomson 
Effect by the Aid of Currents from the Gramme 
Machine. By Professor Tait, . . . .49 
On the Disruptive Discharge of Electricity. By Alexander 
Macfarlane, D.Sc., and P. M. Playfair, M.A., . 50 
Laboratory Note. By Professor Tait, . . . 52 
Monday, 20th January 1879. 
On the Action of Heat on the Salts of Trimethylsulphine. 
No. III. By Professor Crum Brown and J. Adrian 
Blaikie, B.Sc., . . . . . 53 
Experimental Determination of the Electro Motive Eorce of 
the Gramme Magneto-Electric Machine at different 
Speeds. By Professor Tait, . . . . 55 
In the Law of Cooling of Bars. By Professor Tait, . 55 
^ote on the Distribution of Temperature under the Ice in 
Linlithgow Loch. By J. Y. Buchanan, M.A., . 56 
f Turn over. 
