NOVEMBER 26, 1903] 
NATURE 
5) 
bichromate or permanganate is not quantitative. Man- 
ganese dioxide reacts with hydrogen peroxide only in 
presence of sulphuric acid, and even then the reaction is 
incomplete.—The constitution of certain silicates, by Mr. 
C. Simmonds. The results obtained in a series of reduc- 
tion experiments made on metallic silicates indicate that in 
complex silicates the silicon atoms are attached to each 
other, and each to two atoms of oxygen, the unappropriated 
oxygen atoms being those by which the metallic oxides are 
attached to the silica complex.—Constitution of chrysophanic 
acid and of emodin, by Messrs. H. A. D. Jowett and C. E. 
Potter. Chrysophanic acid is shown to be 5 : 8-dihydroxy- 
1-methylanthraquinone, and emodin either 2:5:8- or 
3: 5 : 8-trihydroxy-1-methylanthraquinone.—Conductivity of 
substances dissolved in certain liquefied gases, by Messrs. 
B. D. Steele and D. Mcintosh. The conductivities of 
solutions of a number of substances in liquefied hydrogen 
chloride, bromide, iodide, sulphide, and phosphide have been 
determined.—The behaviour of metallic oxides towards 
fused boric anhydride, by Messrs. C. H. Burgess and 
A. Holt.—Note on some reactions of vanadium tetrachloride, 
by Mr. B. D. Steele. A description of the results obtained 
by the use of vanadium tetrachloride as a chlorinating and 
condensating agent in the synthesis of organic compounds.— 
Studies on comparative cryoscopy, i., the fatty acids and 
their derivatives in phenol solution, by, Mr. P. W. 
Robertson. It is shown that the rate of association for 
fatty acids (normal) rises and falls as the series is ascended, 
and is influenced both by the nature and position of a sub- 
stituent.—Vapour pressures of sulphuric acid solutions, by 
Mr. B. C. Burt.—Additive compounds of sym-trinitro- 
benzene and alkylated arylamines, by Messrs. H. Hibbert 
and J. J. Sudborough.—Interaction between chloric and 
hydriodic acids, by Mr. J. McCrae. A study of this re- 
action, and especially of the rate at which it progresses.— 
3 : 5-Dichloro-1 : 1 : 2-trimethyl-4°4-dihydrobenzene. A cor- 
rection, by Mr. A. W. Crossley. This compound is now 
shown to be the corresponding derivative of unreduced 
benzene.—The estimation of hydroxylamine, by Messrs. 
H. O. Jones and F. W. Carpenter. The method is based 
on the reduction of alkaline copper solutions by hydroxyl- 
amine.—A study of the isomerism and optical activity of 
quinquevalent nitrogen compounds, by Mr. H. O. Jones. 
A number of derivatives of the type N.R.R’/R’/X have been 
prepared, but from these no optically active isomerides 
could be obtained.—The influence of various substituents on 
the optical activity of tartramide, by Messrs. P. F. 
Frankland and A. Slator.—The influence of cyclic radicles 
on optical activity; tartaric-ar- and  ac-tetrahydro-f- 
naphthylamides, furfurylamide and piperidide, by Messrs. 
P. F. Frankland and E. Ormerod, Part of a systematic 
examination of the relationship between rotation and 
chemical constitution of optically active substances.—The 
rotatory power of maldiamide, maldi-n-propylamide, and 
maldibenzylamide, by Mr. J. MeCrae.—Further experi- 
ments with phosphorus sesquisulphide, by Mr. E. G. 
Clayton. The results of the application of Mitscheplich’s 
test to specimens of phosphorus sesquisulphide which had 
been exposed to air under various conditions were given. 
Royal Astronomical Society, November 13.—Prof. 
H. H. Turner, F.R.S., president, in the chair.—Mr. P. H. 
Cowell read a paper on errors in the moon’s tabular longi- 
tude as affecting the comparison of the Greenwich meridian 
observations from 1750 with theory.—The Astronomer 
Reyal read a paper on the large sun-spots of October and 
Neveniber, and the associated magnetic disturbances, and 
exhibited photographs of the sun-spots taken at the Royal 
Observatory, and of the magnetic tracings, showing the 
most considerable disturbance to have been on October 31.— 
Mr. Newall showed and described a series of fine spectro- 
heliographs of the great spot-groups, taken by Prof. G. E. 
Hale.—Mr. Newbegin showed photographs of the 
November sun-spots.—Spectroheliographs of the spot-groups 
taken on October 9 and 31 in K light by Mr. Evershed, 
showing the flocculent masses of faculz surrounding the 
spots, were also thrown on the screen.—Dr. Lockyer con- 
sidered the correspondence of magnetic storms with solar 
prominences was more marked than with sun-spots, and 
pointed out that magnetic disturbances become more decided 
as the prominences approach the poles.—Father Sidgreaves 
NO. 1778, VOL. 69] 
directed attention to the work at Stonyhurst, and to his 
conclusion that sun-spots are not the cause of magnetic 
disturbances, but that both phenomena have a common 
cause:-—Father Sidgreaves then read a paper on a spectro- 
graphic study of 8 Lyre at the Stonyhurst Observatory ; 
he exhibited slides of a series of spectra taken at different 
dates, and explained his theory of the changes in the light 
of the star.—Prof. Turmer gave an account of a method 
of photographing the moon with the surrounding stars, the 
results of which appeared very promising. In order to 
reduce its light the moon was covered by an opaque screen, 
in which was a slit; the screen was drawn slowly across 
the plate, and a sufficient exposure thus given, while 
images were obtained of stars down to about the ninth 
magnitude.—Many other papers were taken as read. 
CAMBRIDGE. 
Philosophical Society, November 9.—Mr. A. C. Seward, 
vice-president, in the chair.—Exhibition of living Gongylus 
gongyloides, a floral mantis, by Captain C. E. Williams. 
The insects exhibited show the pupal or nymph stage in 
the development of this mantis. They were hatched from 
the egg about January 18 of this year, and in the ordinary 
course should have attained the imago or winged state at 
the end of October. Development appears to have been 
arrested by the unsuitable climate of England, and by loss 
ot appetite under confinement. The floral mimicry is 
effected by the foliaceous expansion of the prothorax around 
the insertion of the front pair of legs. This expansion is 
roughly diamond or oval shaped, and on the under side is 
ol a bright azure blue tipped with rose purple at the angles 
and margins; in the centre of this disc is a deeply pig- 
mented black spot of triangular shape. The front pair of 
legs are held closely folded together in the front of the 
coloured disc. The azure coloured disc resembles a small 
flower, and the black spot mimics the tube of a corolla. 
The attitude adopted by the insect when at rest and intent 
on catching its prey is an inverted position below a leaf or 
spray of leaves, the coloured side of the prothoracic disc 
being turned to the brightest light available. Insects, 
especially butterflies, are readily attracted by the floral simu- 
lation. The hinder part of the prothorax is drawn out into 
a long stalk and coloured a light green, enhancing the floral 
resemblance. The rest of the body is shaped and coloured 
to resemble a bunch of dead leaves, and is practically un- 
discernible amid its natural surroundings. The insects ex- 
hibited were brought from Rangoon.—Experiments in wheat 
breeding, by Mr. R. H. Biffen (see p. 92). 
Paris. 
Academy of Sciences, November 16.—M. Albert Gaudry 
in the chair.—A new method of preparation of argon, by 
MM. H. Moissan and A. Rigaut. The argon is prepared 
in four stages, the first three of which, the removal of 
oxygen from the air by heated copper, concentration by 
passing over a mixture of lime and magnesium, twice, are 
identical with the processes worked out by Sir W. Ramsay 
and Lord Rayleigh. In the fourth stage the gas, after 
passing over a lime-magnesium mixture, is treated with 
pure metallic calcium at a dull red heat. Since calcium 
forms a hydride stable at 500° C., this removes at one oper- 
ation the last traces of nitrogen and hydrogen. The 
apparatus produces one litre of pure argon in twelve hours. 
—Mr. G. W. Hill was elected a correspondant in the section 
of astronomy in the place of M. Schiaparelli, elected foreign 
associate.—On the analytical nature of the solutions of 
certain partial differential equations of the second order, by 
M. S. Bernstein.—On the use of the Schrader tacheograph 
in hydrographic work, by MM. F. Schrader and Ch. 
Sauerwein.—On the extraction of oxygen by the partial 
liquefaction of air, by M. Georges Claude. A method is 
described in which only a portion of the air is liquefied 
at a low pressure, and this liquid, with any preliminary 
evaporation, gives a gas containing 92 per cent. oxygen, 
the apparatus giving about 35 cubic metres of this per 
hour.—The measurement of very small angles of rotation, 
by M. Marcel Brillouin. Between the two Nicol prisms 
is introduced a thick plate of Iceland spar with parallel 
faces, cut at 45° to the axis, a half-wave plate, at 45° 
to the principal sections of the spar, and a second plate 
of spar similar to the first. It is possible to measure to 
