240 
thiourea, in which it was shown that in aqueous solutions of 
the compound there appears to be a complex balanced action 
of the kind represented by the equations 
2CSN,H, + Ig == (CSN2H,).lo == (CSN,Hy).** + 21’. 
The addition, to such a solution, of any substance which 
diminishes the ionisation results in increased dissociation, as 
shown by the increased intensity of the colour of the solution. 
PARIS. 
Academy of Sciences, June 23.—M. Bouquet de la Grye 
in the chair.—New researches on batteries founded on the 
reciprocal action of two liquids, by M. Berthelot. The smallest 
amount of hydrogen visible in a voltameter of special form after 
one minute was determined for pressures of 760 and 5 mm., in 
the latter case 0'000014 mgr. This sensitive voltameter was 
then applied to the determination of the minimum electromotive 
force required to produce visible decomposition, and to measure 
the effects produced by liquid batteries —The properties of a 
certain anomaly which is capable of replacing the anomalies 
already known in the calculation of the disturbances of the 
minor planets, by M. O. Callandreau.—The influence of the 
photographic magnitude of stars upon the scale of reduction of 
a negative, by M. Prosper Henry. Instead of comparing the 
results obtained by eye and photographically as has been pro- 
posed by Gill, a purely photographic method is here suggested. 
A portion of the sky is photographed upon a given plate first 
with a short exposure and then with prolonged exposure, the 
pointer micrometer having been slightly displaced between the 
two exposures. The results of the application of this method 
with the large objective of the Paris Observatory are now given. 
—The extension of the kathode hypothesis to nebula, by M. H. 
Deslandres. The light emitted by nebulze has been attributed 
by Arrhenius to electrified particles, by Nordman to Hertzian 
waves, but the author regards both these explanations as in- 
admissible, since, for the same reason, the earth’s atmosphere 
at night should glow with an equal lustre. The kathodic hypo- 
thesis appears to offer a better explanation.—On algebraic 
continued fractions, by M. R. de Montessus de Ballore.—Re- 
searches on actino-electric ppenomena, by M. Albert Nodon. 
When light rays or ultra-violet rays are thrown upon a thin 
conducting plate they give rise, on the dark face of this plate, to 
radiations analogous to X-rays. They differ from kathode rays, 
since they easily pass through metals and black paper, and 
appear to possess properties intermediate between X-rays and 
radium rays.—On a phenomenon observed on an excitor, the 
spheres of which are connected to a Ruhmkorff coil, by M. H. 
Bordier.—The effect of self-induction on the ultra-violet portion 
of spark spectra, by M. Eugene Néculcéa.—On the heats of 
dilution of sodium sulphate, by M. Albert Colson.—The chlor- 
inating properties of a mixture of hydrochloric acid and oxygen, 
by M. Camille Matignon. Gold, tellurium and platinum are 
attacked by a mixture of oxygen and pyrochloric acid at 
temperatures much below the temperature of reaction between 
hydrogen chloride and oxygen. The mixture may in certain 
cases replace chlorine. —On the acidity of pyrophosphoric acid, 
by M. H. Giran. By a study of the heats of neutralisation and 
heats of solution of the sodium pyrophosphates, the conclusion is 
drawn that pyrophosphoric acid is a tetrabasic acid, the acid 
value of each of the hydroxyl groups being identical.—The dis- 
placement of strong bases by ammoniacal copper oxide, by M. 
Bouzat.—On the phenyl migration of phenylethylene and its 
derivatives, by M. M. Tiffeneau. Evidence is given showing 
that in several instances the migration of the phenyl group is 
probable.—Study of the action of selenyl chloride upon ery- 
thritol, by MM. C. Chabrié and R. Jacob.—On dibenzoyl- 
hydrazobenzene, by M. P. Freundler. MM. Biehrirger and 
Busch have recently described a new mode of decomposition of 
diazo-compounds by means of copper powder, in which 
dibenzoyl-hydrazobenzene is stated to be formed. It is 
here shown that the compound really formed in_ this 
reaction is benzanilide, the benzoyl derivative of hydrazo- 
benzene possessing entirely different properties.—Acyl deriya- 
tives of isopyromucic acid: the acetate, benzoate and pyro- 
mucate of isopyromucyl, by M. G. Chavanne.—Chemical 
analysis of Piper Hamechoni or Kissi pepper, by M. A. Barillé. 
—On the phenomena of migration in ligneous plants, by M. G. 
André.—On the composition of ewe’s milk, by MM. Trillat and 
Forestier. —On the estimation of organic nitrogen in water, by 
M. H. Causse.—Analysis of the mode of action of lecithins 
upon the animal organism, by MM. A. Desgrez and Aly Zaky, 
NO. 1705, VOL. 66] 
NATURE 
[JuLy 3, 1902 
— Orthogonal skiagrams of the thorax ; their use for the localisa- 
tion of anomalies and for the measurement of organs, by M. H. 
Guilléminot.—The physiological secretion of the pancreas, by 
MM. C. Delezenne and A. Frouin.—Physiology of the heart in 
some colonies of compound Ascidians, by M. Antoine Pizon.— 
On the idea of depth applied to African metalliferous layers, by 
M. L, de Launay.—On the presence of Carboniferous strata in 
Tidikelt, Sahara, by M. G. B. M. Flamand.—Reproduction of 
some Paleolithic eens drawn on the walls of the grotto of 
Font-de-Gaume (Dordogne), by MM. Capitan and Breuil. 
Four reproductions are given, three of the bison and one of 
reindeer.—On the colouring matter used in the figures 
described in the previous paper, by M. Henri Moissan. The 
colours are ochres formed of the oxides of iron and manganese. 
—The cyclone at Javaugues (Haute-Loire), on June 3, 1902, by 
M. Bernard Brunhes. 
CONTENTS. PAGE 
The New International Catalogue. By Prof. J. B. 
Farmer, F.R.S. . . nai, Beate 1 pee cee 
The Geometry of Cog- Wheels. By Gr Breen alice 
Evolution and Design. By Prof. R. Meldola, 
LoL he ne ee 2EO 
A New Text- Book os Physical ‘chemistry. By 
Vil, ht elem is to cH ayia. ce) 27) 
Our Book Shelf :— 
Serviss: ‘‘Other Worlds”. . . ieee 20 
Brinton: ‘‘ The Basis of Social Relations ; > Shann: 
“* The Criterion of Scientific Truth. pa E. Te. 220) 
*Opere matematiche di Francesco Brioschi” . . 221 
‘*Webster’s International Dictionary of the English 
Language. To which is now added a Supplement 
ofm25;000 Words and) Phrasestu) s-utsn salen meme 
Haldane: ‘‘ Education and Empire. Addresses on 
Wertain' Topics of the Day 2) ). 0.-es aaa 
Letters to the Editor :— 
Mr. Marconi’s Results in Day and Night Wireless 
Telegraphy.—Sir Oliver Lodge, F.R.S.._. . 222 
Kinetic Theory of Planetary OSPR Ee —Dr. E. 
Rogovsky . 222 
The Coloured Sunsets. —Dr. ‘William J. Ss. Lockyer; 8 
J. Edmund Clark... 222 
The Halos of May 1, 8 and 22. _—Rev. T. C. Porter 223 
Matter and Motion in Space.—Sir Hiram S. Maxim 223 
A Method of Treating Parallels. dase shia: )— 
Dr. S. W. Richardson .. . 223 
The First Fruits of the German eter cue! Eapeae 
monm by HH. R.°M. . te caves e) clement = oy (mn mmeaerS 
ByyATeD Elo | 5 eee 
its Documentary 
Rural Education in France. 
The Smithsonian Institution: 
faistory:/ By H. Rl | See eitement te eure! (Une 
Arctic Magnetic Observations. By et C. Chree, 
PRESS bites muiejrcs er te 21217) 
Coronation oncer to Men os Seience tia ipeane meee 
Notes. (J/lustrated.) . . 2 Gk Ee Ste eae eee 
Our Astronomical Column ;— 
Changes on the Moon PRAMS aes EER 
Remarkable Naked-eye Nebulosity Scr) ie; Wa Wer oh eee 
A Theory of Volcanoes . . a, veer SaaS 
The French Geodetic Mission. to the Equator . aeg ee BR 
@pbservations of Nova Persel . . -. 5. - = 4 = «= 233 
New Variable Stars Seb ch) aio Se! 
Delay of the Minimum of U ons «ict Lstaeeiate@acteeetata) PEERED 
Earthquake Notes .. . Senet oo 5 ee! 
Statistical Methods in Bigloeyn evel eee. A ee 
Avian Organogeny. ByW.P.P. ... 235 
Photography as Applied to Architectural Meagere. 
ment and Surveying. (J//ustrated.) ...... + 235 
University and Educational Intelligence .... . 236 
Societies and Academies .. 2 257) 2 «ss = = «238 
