350 Proceedings of the Royal Society 
scale, changed from + to - and back again. It seemed, in fact, 
as if there were alternate changes of atmospheric potential from 
high + to high - , and not, as is usual in such weather, changes 
merely from higher to lower - . The water dropper projected 2J- 
feet from the wall of the College at an elevation of 44J feet from 
the ground below, and discharged at an average about 2’5 cubic 
inches of water per minute. 
2. On the Thermo-Electric Position of Sodium. 
I owe to Mr Dewar’s skill in manipulation the means of deter- 
mining the line of sodium in the thermo-electric diagram. He 
constructed for me a long quill tube of Gferman glass, with platinum 
wires inserted near the ends; exhausted it by means of a Sprengel 
pump, and drew in melted sodium from a bath of paraffin. Exact 
determinations will require considerable time, even with this 
excellent apparatus ; but in the meantime I may state (as a first 
approximation) that the line of sodium is nearly parallel to that of 
palladium, and somewhat above it in the diagram. 
The following Gentlemen were elected Fellows of the 
Society : — 
John Anderson, M.D. 
James Napier, Esq., Glasgow. 
Alexander Hunter, M.D., F.R.C.S.E. 
The following Gentlemen were elected Honorary Fellows, 
to supply the vacancies caused by the deaths of Sir John 
Herschel, Sir Boderick Murchison, John Stuart Mill, Hugo 
Yon Mohl, Wilhelm Karl Haidinger, Baron Justus von 
Liebig, and Gustav Bose : — 
1. British Honorary. 
James Joseph Sylvester, LL.D., Loudon. 
William Hallowes Miller, LL.D., Professor of Mineralogy, Cambridge. 
John Anthony Froude, London. 
2. Foreign Honorary. 
Adolphe Theodore Brongniart, Professor of Botany, Paris. 
Louis Pasteur, Paris. 
Wilhelm Eduard Weber, Gottingen. 
Otto Torell, Professor of Zoology and Geology, Lund, and Director 
Geological Survey of Sweden. 
