310 
NATURE 
[Marcu 3, 1923 

equation of growth of energy of vortices is similar 
to the equation for vital growth given by Brailsford 
Robertson. (2) On the mechanism of extratropical 
cyclones. From the equation for change with time 
of the vorticity of horizontal motion in the earth’s 
atmosphere devised by Hesselberg and Friedmann, 
the most important source of energy of a cyclone 
is in the vorticity of the surrounding field. The 
feeding of a cyclone along the steering surface (of 
the Polar Front theory) is capable of explanation 
as the absorption by the main whirl of the horizontal 
whirl which forms at the surface. 
EDINBURGH. 
Royal Society, February 5.—Prof. F. O. Bower, 
president, in the chair—aA. G. Ogilvie: Physiography 
of the Moray Firth coast. The coastal features along 
the Moray Firth from Golspie to Inverness, thence 
east to Port Gordon, were described. The Firth seems 
to occupy the site of a foundered crustal block, 
bounded by known fractures on the north-west, and 
by possible faults on the south side. Four marine 
platforms occur there, but the detailed levelling shows 
that the inland margin of the highest beach is never 
above ninety feet. Some of the flat expanses of 
gravel and sand, hitherto regarded as remnants of 
this terrace, seem to be outwash aprons from the 
retreating glaciers. Special attention was directed to 
the constructive action of the sea in originating 
shingle bars and sand bars, which unite to form 
forelands and strand plains. 
CAMBRIDGE. 
Philosophical Society, February 5.—Mr. C. T. 
Heycock, president, in the chair—E. A. Milne: 
The escape of molecules from an atmosphere, with 
special reference to the boundary of a gaseous star.— 
J. E. Jones: Free paths in a non-uniform rarefied 
gas with an application to the escape of molecules 
from an isothermal atmosphere. In a gas such as 
exists at the outer fringes of an atmosphere the usual 
formule of the kinetic theory for the calculation of 
free paths are no longer applicable. The necessary 
generalisations have been applied to find the condition 
under which a molecule may escape from an atmo- 
sphere. The total number of molecules lost in this 
way has then been enumerated by a more detailed 
method than has been used hitherto.—J. S. Rogers : 
L series of tungsten and platinum.—R. H. Fowler: 
Contributions to the theory of a-particle phenomena, 
Pt. I. Stopping powers. Pt. II. Ionisation.—C,G. F. 
James: The representation of varieties in space of 
three and four dimensions.—M. J. M. Hill: On the 
fifth book of Euclid’s elements.—G. H. Hardy: A |; 
chapter from the notebook of Mr. Ramanujan.— 
E. C. Titchmarsh: Hankel transforms.—J. P. 
Gabbatt : A generalisation of Feuerbach’s theorem. 
Paris. 
Academy of Sciences, February 5.—M. Albin Haller ; 
in the chair.—G. Bigourdan: The ‘‘Cabinet du Roi” 
and the forgotten discoveries of Rochon. An 
historical account of the installation of this observa- 
tory in 1761, its equipment and an account of the 
astronomical work done there by Noél, Leroy, and 
Rochon.—Charles_ Richet, L. Garrelon, and D. 
Santenoise : The laryngo-cardiac reflex.—A. Blondel : 
Influence of the speed governors controlling turbo- 
alternators on the oscillations -of the electrically 
connected sets. Case of indirect regulation —R. de 
NO. 2783, vol. 111] 

Forcrand: The hydrates of krypton and argon. 
The dissociation pressures of these hydrates have 
been measured at varying temperatures and the 
heats of formation calculated from the results.— 
J. Roudaire-Miégeville: The grapho-mechanical deter- 
minations of systems of real or imaginary solutions 
of algebraical equations. A development of the work 
of Kempe and of Koenigs on tfacing algebraic curves 
by an articulated system.—Charles Fremont: The 
cause of the formation of the elongation at constant 
load near the elastic limit in testing mild steels.— 
Th. Moreux: The probable cause of the anti-solar 
glow.—A. Buhl: The mass and electromagnetic 
fields of Th. De Donder.—Paul Dienes: Tensorial 
geometry.—J. Haag: The distribution of the mole- 
cules of a gaseous mass ; application to the formula 
of Van der Waals.—Albert Pérard: Study of some 
neon radiations with the view of their applications 
to metrology. A comparison of the cadmium line 
(508-582 mu) with five neon lines. The ratios of 
the cadmium and neon lines are not constant. The 
systematic variation proved that the neon lines were 
very close doubles.—L. Bouchet: Application of the 
plane-cylinder electrometer to the determination of 
the inductive capacities of solid substances.—R. de 
Mallemann: Determination of the electromagnetic 
double refraction of active liquids.—René Ledrus: 
The increase of dispersion in photo-electric X-ray 
spectra.—St. Procopiu: The arc spectra of metals 
in various media and in a vacuum. The metals 
studied were copper, gold, zinc, cadmium, magnesium, 
calcium, and aluminium, and the arcs were produ 
in air, hydrogen, coal gas, nitrogen, water, and in a 
; vacuum. All the metals gave a stable arc in nitrogen, 
including magnesium, calcium, and aluminium, with 
which it is difficult to maintain an arc in air. Stable 
arcs were also produced in a vacuum. Details are 
given of the change produced in the lines.—P. 
Dejean: Correlation between the hypothesis of the 
elementary demagnetising field and the theory of 
the molecular field.—E. Darmois and Périn : 
Dextro malic acid and the utilisation of ammonium 
molybdomalate for the resolution of racemic malic 
acid. The dextrorotatory malic acid prepared by 
Walden’s method is partially racemised, and it 
contains about } dextrorotatory acid and } levo- 
rotatory acid. By conversion into ammonium di- 
molybdomalate a separation can be effected.—G. 
Claude: The application of coke oven gas to the 
synthesis of ammonia. After removal of benzol by 
oil and carbon dioxide by lime water, the remaining 
gases are separated by fractional condensation, the 
hydrogen passing on to the ammonia apparatus.— 
Raymond Delaby: The characterisation of the 
alkylglycerols.—Léon Bertrand and Antonin Lanquine: 
Extension of the duplicatures provengales under the 
Cheiron layer (Alpes-Maritimes) to the west of the 
Var valley.—Filippo Eredia: The dryness of Italy 
during the year 1921.—E. and G. Nicolas: The 
influence of hexamethylene-tetramine and formalde- 
hyde on the internal morphology and chemical 
changes in the bean.—A. Polack: The physiological 
determinism of the accommodative reflex of the eye. 
—J. Dragoiu, F. Vlés, and M. Rose: Cytological 
consequences of the lowering of the hydrogen ion 
concentration on the evolution of the egg of the sea- 
urchin.—A. Goris and P. Costy: The urease of 
fungi. The urease from Boletus edulis was studied : 
detailed accounts of the effects on the enzyme of 
heat, acids, alkalies, neutral salts, and antiseptics 
are given.—L. G. Seurat: The fauna of penetration 
of South Tunisian rivers—R. Herpin: The sexual 
relations in Perinereis cultrifera—L. Léger and E. 
Hesse: A fungus of the Ichthyophonus type, a 
parasite of the intestine of the trout. 
nee _— 
