Jury 25, 1912] 
NATURE 
547 
The carbide is also magnetically harder at ordinary 
temperatures) and possesses greater coercive . force, 
although, like iron, it is.magnetically very soft at | 
temperatures near the transition point. In conse- 
quence of these facts, the effect of heat upon the 
residual magnetism of an arinealed steel rod is peculiar 
and at first sight mysterious. As the temperature 
rises the residual magnetism falls continuously until 
it becomes zero in the neighbourhood of 200° C. It 
then changes sign and reaches a maximum negative 
value at about 220° C. Beyond this, the negative 
magnetisation decreases slowly, and finally becomes 
imperceptible between 7oo° C. and 800° C. If the 
rod is cooled from 800° C. it remains without per- 
ceptible polarity as the temperature falls; but if the 
heating is interrupted before the whole of the 
residual magnetism is destroyed the behaviour 
on cooling is quite different. 
EDINBURGH. 
Royal Society, July 1.—Dr. Horne, F.R.S., vice- 
president, in the chair.—The late Dr. Alexander Bruce 
and Dr. J. W. Lawson: Multiple neuroma 
of the central nervous system; their structure 
and histogenesis. The paper was based upon the 
record of a rare condition found post-mortem, in which 
a number of small nodules were discovered scattered 
through the spinal cord and the medulla oblongata; 
and its main import was the question of the origin 
and relation of the nerve fibre to the nerve cell. Of 
the two views (1) that the fibre is an outgrowth of 
the cell, (2) that the fibre arises separately from the 
cell and afterwards unites with it, the latter seemed 
to fit in better with the observations.—Dr. G. E, Allan 
and John Brown: The transformation of ferric oxide 
into magnetic oxide. On the experimental side the 
paper was an elaborate investigation into the magnetic 
changes which accompany heating and.cooling of 
ferric oxide. These changes indicated — certain 
chemical transformations. One of the conclusions 
was that magnetite may be formed at a comparatively 
low temperature in rocks which contain haematite. 
Paris. 
Academy of Sciences, July 8.—M. Lippmann in the 
chair.—J. Boussinesq: Errors,» sometimes important 
from the theoretical point of view, introduced in the 
simplifications necessary for the consideration of actual 
systems.—G,. Bigourdan: Time signals, anda method 
of producing them.—Henry Le Chatelier: The deter- 
mination of atomic weights by Hinrichs’s method. 
The author points out the fallacy of this method of 
calculating the ‘“‘true’’ atomic weights.—El]. Metch- 
nikofi and Al. Besredka: Inoculation against typhoid 
fever. Experiments made on- chimpanzees showed 
that, after injection under the skin, the bacilli were 
absent from the general circulation and from the 
excreta, and that the animals did not act as carriers 
of typhoid. The method has since been.used in a 
large number of cases, and a full account will be 
published in the Annales de l'Institut Pasteur.—M. 
Gouy : Pressure at the surface of the sun. The author 
concludes that the visible portions of the sun consist of 
gases and ‘vapours in a state of very great rarefaction. 
R. de Forcrand: The system water-cyclohexanol. 
The existence of a hydrate is possibly indicated by the 
solidification curve.—A. Buhl: The extensions of the 
formula of Stokes.—Ch. N. Moore: The factors of 
convergence in double series, and on the double series 
of Fourier.—Patrick Browne ; The generalised problem 
of Abel and its applications.—Jean Chazy: The limita- 
tion in degree of the coefficients of differential alge- 
braical equations with fixed critical points.—Arnaud 
series.—René. Garnier: The representation of. the in- 
tegrals of irreducible equations of the second order, 
with fixed critical. points, by means of the theory of 
linear equations.—A. Guillet and M. Aubert; Expres- 
sion for the force between two electrified conductors. 
—A,. Tian: Variations in the radiation of the quartz- 
mercury lamp with treatment and time of use. The 
formation of hydrogen peroxide from water containing 
oxygen, and also the ozonisation of oxygen, are pro- 
duced by rays of very short wave-length. On the 
other hand, ozone and the peroxide are energetically 
decomposed by.rays in the middle portion of the ultra- 
violet: The feeble production of. hydrogen peroxide 
and of ozone by quartz-mercury lamps with a high 
voltage is due, not to a diminution in the radiation 
producing these substances, but to a great increase in 
the rays which cause their destruction.—L. Dunoyer : 
The conductivity of sodium vapour. The conductivity 
of pure sodium vapour does not differ greatly from 
that of ordinary gases.—G. Millochau : A contribution 
to the study of oscillatory discharges._—Ph. A. Guye: 
The law of mass-action. Considerations as to the 
conditions under which the law of mass-action is 
rigorously applicable-——Eugene Wourtzel: Density and 
compressibility of nitrosyl chloride. The exact weights 
of a litre of NOC] at 0° C., and under pressures of 
287 mm. and 720 mm., were determined in order to 
control the atomic weight of chlorine and to examine 
the deviations of nitrosyl chloride from Boyle’s law. 
The weight of one litre (N.T.P., latitude of 45°, at 
sea-level) was 2°9919 grams, and the molecular weight 
thus found differs by only 1/5500 from the calculated 
value, taking N=14 008 and Cl=35'460, a difference 
which is within the limits of experimental error.— 
C. Chéneveau: The viscosity of solutions. Experi- 
ments show that if the existence of hydrates in solu- 
tion be admitted, those indicated by the viscosity 
measurements are not in general the same as those 
indicated by measurements of the refractive index.— 
M. Chouriguine: The alloys of platinum with 
aluminium. These metals form a coloured compound 
of the formula PtAl,, and also another compound 
richer in platinum.—M. Laségue: Chlorous acid. 
Barium chlorite was obtained by passing the gases 
produced by the reduction of chloric acid by tartaric 
acid into baryta water. It was purified by conversion 
into the insoluble yellow lead chlorite, and then re- 
| converted into chlorite of barium, from which the acid 
was obtained by the action of sulphuric acid. _Chlorous 
acid is very unstable, and decomposes according fo 
the equation 4HClO,=2H.0+3CIl0,+Cl.—Marcel 
Guichard and Pierre Roger Jourdain; Gases evolved 
from aluminium.—Paul Lebeau: A new determination 
of the atomic weight of uranium. The - salt 
UO.(NO,).,2H,O (which does not lose its water even 
on exposure over phosphorus pentoxide) is reduced to 
UO, by heating in a current of hydrogen. The ratio 
thus found gives U=238'5, a number agreeing exactly 
with that found by Richards and Merigold by analysis 
of the tetrabromide, UBr,.—Henri Golblum and Mlle. 
Héléne Gunther ; Electrolytic estimation of manganese 
and its separation from iron.—J. B. Senderens and J. 
Aboulenc: Catalytic production, in the wet way, of 
esters of the cyclohexanols. The best yields of esters 
are obtained by heating the mixture of cyclohexanol 
and organic acid with 3 per cent. by volume of sul- 
phurie acid to 100°—110° C., for about an hour.— 
Maurice Lanfry: Action of hydrogen peroxide on 
acetothienone.—E. Léger: Constitution of the aloins 
from Natal aloes. These substances are glucosides 
derived from d arabinose.—J.° Pavillard ; Concerning 
Diplopsalis lenticula.—A. Eckley Lechmere : Some new 
moulds from the Ivory Coast.-M. Radais and A. 
Denjoy: The absolute convergence of trigonometrical 1 Sartory: Comparative toxicity of various poisonous 
NO. 2230, VOL. 89] 
