Januaky 17, 1907 | 
the Kameruns frontier. The rocks are crystalline, prin- 
cipally gneisses and schists, with later granites, pegma- 
tites, and basaltic dykes, surrounded on the north, west, 
and south by Cretaceous sediments. For purposes of de- 
scription the series is divided under nine headings, accord- 
ing to locality and petrographical character; and it is 
concluded that; neglecting the basaltic dykes, two broad 
groups may be distinguished—the one characterised by the 
presence, the other by the absence, of foliation. In the 
former the foliation tends to be lost, giving a passage 
between types which petrographically are acid orthogneisses 
and granites.—The crystalline rocks of the Kukuruku Hills 
(Central Province of southern Nigeria): J]. Parkinson. 
In this paper a short account is given of the crystalline 
rocks found in the Central Province of southern Nigeria, 
between the station of Ifon (north of Benin City) and the 
northern Nigerian frontier. The rocks fall under two 
heads :—(a) a group of gneisses, and (b) a group of schists. 
Royal Microscopical Society, Decemher 19, 1906.— 
Dr. D. H. Scott, F.R.S., president, in the chair.—Micro- 
scopic study of strain in metals: F. Rogers. The author 
described the nature of the fatigue of steels which is 
brought about by submitting them to alternating stresses of 
a certain magnitude. The nature of the effects in the 
ferrite of steels is different from that in soft iron, and the 
effects in pearlite depend upon the type of pearlite. An 
important difference exists between steels as rolled, or 
annealed below about 750° C., and steels annealed at 
higher temperatures, i.e. more or less overheated. In the 
former, the outcrops of surfaces upon which slip has re- 
peatedly occurred are very numerous, short and crooked, 
and the surface parallel to the direction of stress becomes 
ruffled. In the latter ‘type, the outcrops are fewer, less 
crooked, and longer, and the surface is practically un- 
ruffled. A relation is found to exist between the ruffling 
and the Liiders’s lines which are found upon statically- 
strained pieces, and this leads to the theory that specimens 
of the ‘‘ normal ’’ group endure fatigue better than “ over- 
heated’? specimens, because the permanent and injurious 
microscopic strains are more minutely subdivided and 
uniformly distributed in the former than in the latter. 
There is a stage in the life of a piece of steel enduring 
fatigue, after which, though it is far short of final rupture, 
annealing is futile, if not actually harmful. Pieces in this 
stage if heated to 250° C. or higher, and then fatigued to 
rupture, show heat-tint marks on the ultimate fracture, 
which map out the portion of fracture which was suffici- 
ently open at the time of heating for air to enter. 
Paris. 
Academy of Sciences, January 7—M. A. Chauvean 
in the chair.—The distillation of alloys of silver and 
copper, silver and tin, and silver and lead: Henri Moissan 
and Tosio Watanabe. Alloys of the above-named metals 
were heated under comparable conditions in the electric 
furnace, the current being maintained at 500 amperes at 
110 volts. The original alloy was analysed, and also the 
ingot remaining in the graphite crucible after the heating. 
It was found that the metal most easily volatilised was 
lead, followed by silver, copper, and tin, tin having the 
highest boiling point of the four. The results are in 
general agreement with the experiments of Krafft on the 
distillation of small quantities of metals in a kathode 
vacuum.—The results of the micrometric measurements 
made during the eclipse of August 30, 1905, at Roquetas 
and at Saint Genis Laval: Jean Merlin. The value 
adopted by Newcomb for the constant of lunar parallax 
is not appreciably in error, and a better value cannot be 
deduced from the above observations. A certain number 
of the relative positions of the sun and moon given in the 
Connaissance des Temps require correction.—A theorem 
of Heine and a theorem of Borel: A. Schcenflies.— 
Turbines with a flexible axis: L. Lecornu. In _ high- 
speed impact turbines of the Laval type there are certain 
advantages connected with the use of a flexible axis. The 
present paper is concerned with the effects of this flexible 
axis upon the movements of the centre of gravity of the 
system, taking into account the small variations of the 
angular velocity of the turbine disc.—The theory of the 
magnetic properties of iron beyond the temperature of 
NO. 1942, VOL. 75 | 
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transformation: Pierre Weiss.—Ihe measurement of the 
radio-chromometric degree by the electrostatic voltmeter in 
the utilisation of the R6ntgen rays in medicine: J. 
Bergonie. The voltage of the Crookes’s tubes being 
measured by an electrostatic voltmeter indicating up to 
60,000 volts, it was found that whatever the intensity of 
the current traversing the tube, if the voltage measured 
by the voltmeter v kept constant, the rays emitted by 
the tube are always sensibly of the same radio-chromo- 
metric degree. For increased voltages of the tube the 
rays become more penetrating, the variable intensities of 
current passing through the tube being without effect. 
Finally, for tubes of different patterns, unequally used, and 
carrying different intensities of current, provided that the 
voltages are kept equal the radio-chromometric degree of 
each is the same.—The ultra-violet phosphorescent spec- 
trum of fluorspar. The variations of the phosphorescent 
spectrum of the same element in the same diluent: G. 
Urbain and C. Scal. The phosphorescence spectrum of 
an element cannot be considered as constant, but depends 
on the proportions in which it is present in the diluting 
medium.—The chlorination of organic compounds in the 
presence of thallous chloride: V. Thomas. The results 
obtained by the substitution of chloride of thallium for 
ferric chloride as a catalytic agent in chlorination are not 
essentially different in the two cases, complex mixtures 
being found.—The alkaline reduction of p- and m-nitro- 
benzophenone: P. Carré. The complete reduction with 
zinc dust and caustic soda is not possible without affecting 
the ketonic group; the mixture of azo- and azoxybenzo- 
phenone resulting from this reduction furnished p-hydrazo- 
benzophenone on treatment with ammonium hydrosulphide. 
—The use of polarised light for the detection under the 
microscope of starches composed of rice and maize in 
wheat flour: G. Gastine. An improvement of a method 
proposed in an earlier paper.—Fluorine in mineral waters : 
P. Carles. The author has improved his method for the 
detection of traces of fluorine in mineral waters, and gives 
approximate determinations of the amounts present in 
ninety-three waters of different origin.—Artificial growths : 
Stéphane Leduc. An account of the influence of the 
medium in which the artificial cells are produced.—The 
influence of temperature and the hygrometric state of the 
surrounding atmosphere on the preservation of eggs: M. 
de Loverdo. The most favourable conditions for the 
preservation of eggs are a temperature kept exactly at 
—1° C., and a hygrometric state as near as possible to 
78 per cent. saturated.—The annelids collected by the 
French Antarctic Expedition: Ch. Gravier.—The origin 
of the centrosome: J. Kumstler.—The regulation of the 
nycthemeral cycle of temperature and its inversion in the 
aged: Ed. Toulouse and H. Piéron.—The Cretaceous 
strata of the eastern Atlas in Morocco: W. Kilian and 
Louis Gentil.—The value of the magnetic elements at the 
Val-Joyeux Observatory on January 1: Th. Moureaux. 
New Soutu WALEs. 
Royal Society, November 7. 1906.—Prof. T. P. Anderson 
Stuart, president, in the chair.—Notes on some native 
tribes of Australia: R. H. Mathews. The author repro- 
duced some information he had collected during many years 
past among the aborigines of different portions of the 
continent respecting their sociology, laws relating to food, 
methods of avenging deaths, and so on. He also briefly 
touched upon their language, and some curious beliefs 
held by the natives concerning metempsychosis, or re- 
incarnation of souls.—Note on the Silurian and Devonian 
rocks occurring to the west of the Canoblas Mountains, 
near Orange, New South Wales: C. A. Sissmilch. The 
area referred to comprises a large portion of the parish 
of Barton and a small portion of the parish of Bowan, 
county of Ashburnam, and is about fifteen miles south- 
west from Orange. 
Care Town. 
South African Philosophical Societv, November 28. 
1906.—Dr. J. C. Beattie, president, in the chair.—Notes 
on the morphology and biology of Hydnora africana, 
Thunb.: Dr. Marloth. The genus Hydnora comprises 
several species (about seven), which are confined to the 
African continent. They are all parasites which grow on 
