PROCEEDINGS 
OF THE 
ROYAL SOCIETY OF EDINBURGH. 
vol. xi. 1880-81. No. 109. 
Ninety-Eighth Session. 
Monday , 21 st February 1881. 
Professor ELEEMING JENKIN, Vice-President, 
in the Chair. 
The following Communications were read : — 
1. Effects of Strain on Electric Conductivity. By M. August 
Witkowski. Communicated by Sir William Thomson. 
2. On the Effect of Moistening with Water the opposed 
Metallic Surfaces in a Volta-Condenser, and of substi- 
tuting a Water- Arc for a Metallic-Arc in the Deter- 
mining Contact. By Sir William Thomson. 
3. On Vortex Sponge. By the same. 
4. On some Transformations connecting General Determinants 
with Continuants. By Mr Thomas Muir. 
5. Note on the preceding Paper. By Professor ChrystaL 
VOL. XI. 
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