IV 
Contents. 
PAGE 
Preliminary Report on the Tunicata of the u Challenger 55 Expedi- 
tion. Part III. By W. A. Herdman, D.Sc., . . . 52 
On the Histology of the Pedicellarise and the Muscles in Echinus 
sphwra , Forbes. By Mr Patrick Geddes, E.R.S.E., Lecturer on 
Zoology in the School of Medicine, Edinburgh, and Mr Frank E. 
Beddard, B.A., Assistant-Demonstrator of Zoology, Oxford, . 88 
Additional Note on an Ultra-Neptunian Planet. By Professor 
George Forbes, . . . . . . ,89 
On some Effects of Rotation in Liquid Jets. By Professor Tait, . 94 
Note on the Influence of Temperature-Change of Conductivity on 
the Conduction of Heat in Solids. By Professor Tait, . . 94 
Obituary Notices of Fellows who died in the course of Session 
1880-81 : — Mr Thomas Key, Dr William Lassell, Mr Maurice 
Lothian, Mr Mungo Ponton, Mr Thomas Knox, the Hon. Lord 
Ormidale, Professor Sharpey, . . . 95-116 
On a Simple and Accurate Method of determining the Longitude of 
a Place by a Single Observer, without the aid of any instrument 
for measuring time. By Professor G. Forbes, . . .117 
Stilbite, from Kerguelen’s Island. By A. Liversidge, Assoc. Royal 
School of Mines, Professor of Geology and Mineralogy, University 
of Sydney. Communicated by Mr J. Y. Buchanan, . .117 
On a Simple Form of Selenium Cell, and Experiments therewith. 
By Professor James Blyth, . . . . . .119 
Dust, Fogs, and Clouds. By Mr John Aitken, . . . 122 
Note on Thermal Conductivity, and on the Effects of Temperature- 
Changes of Specific Heat and Conductivity on the Propagation of 
Plane Heat Waves. By Professor Tait, . . . .126 
Note on a Simple Method of Showing the Diminution of Surface 
Tension in Water by Heat. By Professor Tait, . . .131 
On the Cell-Walls of Hepatic Cells. By John Berry Hay craft, 
M.B., B.Sc., F.R.S.E., Senior Demonstrator of Physiology in the 
University of Edinburgh, . . . . . .131 
Effects of Strain on Electric Conductivity. By M. August Witkowski. 
Communicated by Sir William Thomson, .... 135 
On the Effect of Moistening with Water the opposed Metallic Surfaces 
in a Volta-Condenser, and of substituting a Water- Arc for a Metallic- 
Arc in the Determining Contact. By Sir William Thomson, . 135 
On Vortex Sponge. By the Same, . . . . .135 
On some Transformations connecting General Determinants with 
Continuants. By Mr Thomas Muir, . . . .135 
Note on the preceding Paper. By Professor Chrystal, . .135 
Introductory Address by the President, the Right Hon. Lord Mon- 
creiff. (Continued from p. 2), . . . . .136 
On the Intrinsic Muscles of the Mammalian Foot. By Dr D. J. 
Cunningham, . . . . . . .162 
On the Expansion of Rational Fractions, &c. By Mr A. H. Anglin, 162 
Algebra of Relationship. Part III. By A. Macfarlane, M.A., D.Sc., 
FeR.S.Ec. ........ 162 
