206 
NATURE 
[ FEBRUARY I0, 1923 

called “‘inertia’’ terms are neglected and a solution 
is found which satisfies the boundary conditions on 
the cylinder and makes the velocity only logarithmic- 
ally infinite in one direction at infinity. The relative 
velocity increases comparatively slowly with the 
distance from the cylinder, and the solution should 
give a fairly good approximation to the motion at 
small distances from the cylinder. First, the elliptic 
cylinder is treated as a limiting case of the ellipsoid. 
The solution, which in the case of the ellipsoid 
satisfies the boundary conditions and those at infinity, 
leads to a solution for the elliptic cylinder. The 
plane laminz, both along and perpendicular to the 
stream, are considered as limiting cases, and further, 
the motion due to the circular cylinder is deduced as 
a special case of the elliptic cylinder. Secondly, the 
solutions for the elliptic and circular cylinders are 
obtained directly from the equations of motion. 
Finally, stream-lines, curves showing vatiation of 
velocity along stream-lines and curves of constant 
velocity are drawn for three limiting cases —W. 
Jevons: The line spectrum of chlorine in the ultra- 
violet (Region \ 3354-2070 A.). Observations of the 
spectrum of the chlorine discharge tube, which have 
not hitherto extended lower than \ 3276 A. (Eder and 
Valenta), have been continued so far as \ 2070 A. by 
means of to-feet grating and quartz-prism spectro- 
graphs. Wave-lengths and wave-numbers of nearly 
200 newly observed Cl lines are recorded, together 
with the effects of variations of capacity on the 
intensities of more than 100, The constant differ- 
ences (Av) 40-4, 67-1, 107-5, found by Paulson in 
pairs and triplets above \ 3276 A. recur in a few pairs 
below that point. The significance of these separa- 
tions in relation to the analysis of the spectrum, how- 
ever, appears doubtful, since there is no apparent 
regularity in the intensities of the lines involved, and 
no triplets having these separations have been de- 
tected in the region under investigation—M. H. 
Evans and H. J. George: Note on the adsorption of 
gases by solids and the thickness of the adsorbed 
layer. The amount of carbon dioxide adsorbed by 
unit surface of glass, at a pressure approximating to 
one-sixth of an atmosphere, suggests that the carbon 
dioxide is condensed on the surface of the glass in a 
liquid layer having a thickness equal to between five 
and six times the diameter of the molecule of the gas. 
By combining this result with the published figures 
of Milfarth (Ann. d. Physik, 1900, vol. 3, p. 328) on 
the relative adsorption by glass of the gases acetylene, 
nitrous oxide, carbon dioxide, sulphur dioxide, and 
ammonia, it is found that these gases are adsorbed by 
the surface to such an extent that if they were present 
as liquid layers, the thickness of the layers would 
vary from (in the case of acetylene) three, to (in the 
case of ammonia) forty molecular diameters. A 
direct determination of the degree of adsorption of 
ammonia gives a value of the same order as that 
calculated from Miilfarth’s data. The results are in 
disagreement with Langmuir’s recent generalisation 
that the forces of attraction’exerted by a surface do 
not extend to a distance greater than the diameter of 
one molecule. 
Linnean Society, January 18.—Dr. A. Smith Wood- 
ward, president, in the chair.—G. H. Wilkins: (1) A 
dried vegetable mass made from a variety of wild 
plants, Chenopodium and others. The plants are 
now important in the food-supply of the Russian 
peasantry ; they are dried, pounded to a fine flour, 
and mixed with rye to make coarse cakes. (2) The 
Shackleton - Rowett expedition in the Quest to the 
Antarctic Regions. On St. Paul’s Rocks no plants 
save a few Algze were found, but at South Georgia, 
an island about 100 miles long and 20 miles broad, 
NO. 2780 VOL. 111] 



a considerable collection was made, and reindeer 
thrive. Lichens and mosses only were observed on 
Elephant Island; at Tristan da Cunha 16 species 
were gathered.—E. G. Baker: The flora of Gough 
Island ; 20 flowering plants and ro ferns are known. 
The only small trees on the island are Phylica and 
Sophora. There is a new species of Apium allied to 
A. austvale Thouars, but having broad cuneiform 
segments to the leaves. The widely-spread fern 
Lomaria Boryana Willd. reaches a height of from 2 to 
3 feet.—Miss Helena Bandulska: The cuticular struc- 
ture of certain dicotyledonous and coniferous leaves 
from the Middle Eocene flora of Bournemouth. Three 
new species of dicotyledonous leaves are described 
from their cuticular structure. The name Dicotylo- 
phyllum is proposed for such leaves of uncertain 
affinity. The cuticles of some fossil conifers were 
compared with known recent and fossil forms. Thus 
Avaucarites Gépperti Sternberg, Taxodium europeum 
Sap. and Sequoia Tournalii Sap. are considered on 
the evidence of cuticular structure to be specifically 
distinct. 

Aristotelian Society, January 29.—Prof. A. N. 
Whitehead, president, in the chair—Rev. Leslie J. 
Walker: A new theory of matter. The general 
trend of scientific thought seems to indicate a return 
to the basic principles of the Aristotelian philosophy, 
a philosophy in which the concept of energy is no less 
fundamental than it is in modern scientific theory. 
On the other hand, the atomic theory, the electron — 
theory, and still more especially the quantum theory, 
would seem to indicate that we shall sooner or later 
be forced to give up the notion of an infinitely divisible 
continuum, and to substitute in its place a continuum 
composed of definite and indivisible units. There 
was, prior to Aristotle, a theory which treated the 
continuum as a structure composed of unit-magni- 
tudes in immediate relation or “‘ contact’ one with 
the other. It is possible to develop this theory on 
Aristotelian lines, taking as the basic assumption that 
the characteristic of ether-particles is to be in im- 
mediate relation with six and only six other particles, 
and that the characteristic of mass-centres is that 
they may be in immediate relation with either more 
or fewer than six other particles, possibly with four 
as a minimum and eight asa maximum, The primary 
type of change would thus be a change in the im- 
mediate relation 6f particles one to another, and the 
primary law governing such change an ever-increasing 
approximation towards equal distribution of the 
ether-particles with respect to the mass-centres. The 
theory gave rise to several features analogous to those 
which are of primary importance in the electron 
theory. 
EDINBURGH. 
Royal Society, January 8.—Lord Salvesen in the 
chair—J. S. Dunkerly: Encystation and reserve 
food formation in Tyvinema lineave. The paper 
showed that the process of conjugation and encyst- 
ment in the rhizopod, Trinema lineare, is followed 
by nuclear fusion, and the formation of reserve food 
material in the cyst is apparently due to the activity 
of the extra-nuclear chromidial mass.—Lancelot 
Hogben: Photo-micrographs were shown illustrating 
a new technique for removal of the pituitary glan 
in frogs and toads; also photo-micrographs of 
changes in melanophore response incident to partial 
and total extirpation of the gland. 
- 
SHEFFIELD. 
Society of Glass Technology, January 17.—Prof. 
W. E. S. Turner, president, in the chair.—W. H., 
Hatfield: Stainless steel, with some consideration of 
