May 27, 1909] 



NA TURE 



389 



the collimator which carries the analyser, to move 

 simultaneously through equal angles by means of a simple 

 form of link motion. A source of monochromatic light (a 

 small glow-lamp in a coloured globe) is rigidly attached 

 to, and moves with, the telescope. To enable opaque 

 liquids to be examined, the graduated circle over which 

 the telescope and collimator move is fixed in a vertical 

 plane. Fusible substances are contained in a porcelain 

 capsule, which can be heated by steam or by an electric 

 current, so that a reflecting liquid surface is thus obtained. 

 Further observations on the powdery scab of the potato, 

 Spongospora subterranea (Wallroth) : Prof. T. Johnson. 

 The author brought forward evidence in favour of the 

 view that the organism responsible for the scab is a 

 true slime-fungus identical with the Erysihe subterranea 

 described by VVallroth in 1S42. He also gave an account 

 of experiments conducted last year to prevent the scab. 



Paris. 

 Academy of Sciences, May 10. — M. Emile I'icard in the 

 chair. — Critical examination of the monochromatic images 

 of the sun with the hydrogen lines : H. Deslandres and 

 L. d'Azambuja. A further instalment of the results 

 obtained with the large spectroheliograph at Meudon, a 

 description of which instrument is given in an earlier 

 paper. For the red hydrogen line, the first-order spectrum 

 with a grating gave sutTicient dispersion. With this 

 arrangement, not only has the entire line been isolated, 

 but also separately the centre of the dark line and its 

 edges. The image of the centre, representing the upper 

 layer of hydrogen, has been compared with the correspond- 

 ing layer K, of calcium, and was found to present the 

 same characters, although somewhat weakened. Some 

 of the phenomena previously observed are shown to be due, 

 not to peculiarities in the emissive or absorptive power 

 of hydrogen, but to an instrumental cause, a defect of the 

 spectroheliograph. — The unsymmetrical enlargement of the 

 lines of the arc spectrum and their comparison with those 

 of the solar spectrum : Ch. Fabry and H. Buisson. 

 When the arc is produced between iron poles in a vacuum 

 it is less luminous than when produced at atmospheric 

 pressure and all the lines are much finer. Certain lines, 

 which in the air arc are distinctly thickened, in a vacuum 

 cannot be distinguished from the others. The observations 

 form a complete confirmation of the explanation given by 

 the authors of the anomalies observed in the comparison 

 of the sun and arc spectra. — A recent note of M. Stekloff : 

 E. Goursat. A claim for priority. — Problems of elasticity 

 in two dimensions : C. KolossolT. — The nomographic re- 

 presentation of equations with four variables : Maurice 

 d'Ocagrne. — An arrangement of a carrying surface for an 

 aeroplane : Maurice Caron. — .^n apparently abnormal fact 

 which occasionally occurs in commercial transformers : 

 M. Gacogrne and A. Leaute. The anomaly described is 

 due to the capacity of the transformer. — An influence of 

 radium on the velocity of crystallisation : Louis 

 Frischauer. Comparative measurements were taken of 

 the rate of crystallisation of droplets of surfused sulphur, 

 a portion of the sulphur only being exposed to the radia- 

 tion from radium salt. In the latter case the velocity of 

 crystallisation was increased. The radium emanation gave 

 a similar result, but exposure to the Rontgen rays was 

 without influence. It would thus appear that it is the 

 a rays which are active in this respect. — Thermo- 

 endosmosis : M. Aubert. — The charge of a negative ion 

 of a flame : Georges Moreau. The charge found 

 e^^-^Xio-", and may be compared with the value for 

 the charge of an electron found by Millikan (406). Perrin 

 (41), and Rutherford (4-65), all divided bv io'°. — The 

 discharge of inductors : E. Caudrelier. — The teleauto- 

 copyist for the transmission of images to a distance : 

 Laurent S€mat. A description is given of the apparatus 

 and of the method of securing the necessary iso- 

 synchronism. All the operations take place in daylight, 

 and are controlled by purely mechanical methods, neither 

 photography nor selenium being used. About five minutes 

 are required to transmit a plate measuring 7 cm. by 

 12 cm. — Wireless telephony : MM. Colin and Jeance. 

 The special advantages of the apparatus described are the 

 arrangements of the negative electrodes of the arcs to 

 ensure steadiness, the utilisation of an intermediate circuit 



NO. 2065, VOL. 80] 



for giving a simple, constant oscillation, and the arrange- 

 ment of the microphones. — The radium emanation : A. 

 Debierne. The volume of emanation in equilibrium with 

 I gram of radium was found to be, in mean, 0-58 cubic 

 millimetre, in close agreement with the results of Ruther- 

 ford and Royds, but much smaller than the 7 cubic milli- 

 metres of Ramsay and Cameron. From the curves of 

 decrease of the intensity of the radiation a diminution to 

 one-half takes place in 381 days. — The anhydrous combina- 

 tions of thorium chloride with the alkaline chlorides : Ed. 

 Chauvenet. .\nhydrous thorium chloride combines with 

 the alkaline chlorides, giving compounds of the type 

 ThCl,.2MCl with the metals Li, Na, K, Rb, and Cs, and 

 ThCl.,.4MCl with Rb and Cs only. Ammonium chloride 

 forms the exceptional compound ThCIi.NH.Cl. — Benzoyl- 

 acrylic acid. The condensation of glyoxylic acid with 

 some ketones : J. Bougrault. In alkaline solution 

 glyoxylic acid readily condenses with acetophenone and 

 analogous ketones, forming diphenylacetic acid or 

 analogous acids. Dianisylacetic and diperacylacetic acids, 

 prepared by this reaction, are described. — The modifica- 

 tions of anthesterol and its benzoate : M. T. Klobb. — A 

 nephelinic syenite from the Transvaal : H. A. Brouwer. 

 — The energy necessary for kneading by machinery : M. 

 Ring^elmann. — Observation of ovules of the rabbit with 

 two germs, contained in a common envelope of albumen 

 secreted by the oviduct : CI. Regraud and G. Dubreuil. 

 — A popular remedy for cancer : Robert Odier. — The 

 regulation of the secretions by d'Arsonvalisation ; Foveau 

 de Courmelles. The high-frequency treatment leads to 

 increased secretion of urea, uric acid, and chlorides, 

 together with a diminution in the amount of phosphate 

 eliminated. — Costiasis and its treatment in young trout : 

 Louis Ueger. The use of a weak solution of formalin 

 (35 c.c. to 40 c.c. of the 40 per cent, solution in 100 litres 

 of water) is suggested for destroying the parasite (Costia 

 necatrix), the cause of the disease. The young trout are 

 not injured by this solution. Another trout disease gyro- 

 dactylosis, is cured by the same treatment. 



May 17. — M. Emile Picard in the chair. — Biaxial 

 crystallised liquids : Fred. Wallerant. Liquid azoxyanisol 

 shows the true properties of biaxial crystals. This is 

 regarded as an argument in favour of the absolute identity 

 of liquid and solid crystallised bodies. — A new Australian 

 Onychophorus : E. L. Bouvier. The new species 

 resembles Peripatoides Stiteri, but this resemblance is only 

 superficial, since many distinctive characters are different. 

 — Surfaces of total constant curvature : C. Guichard. — 

 The value of the invariants p and p„ for surfaces of the 

 fourth order with double isolated points : L. Remy.— The 

 residues of measurable functions ; Fr^d^ric Riesz. — The 

 principle of Dirichlet and the development of harmonic 

 functions in polynomial series : Serge Bernstein. — Linear 

 differential equations and uniform transcendentals of the 

 second order : Ren^ Garnier. — An example of the Zeeman 

 effect, positive and longitudinal, in the emission spectra of 

 vapours : A. Dufour. — The chromatic circle according to 

 Young's hypothesis : A. Rosenstiehl. The new chromatic 

 circle designed bv the author gives colours possessing the 

 following qualities of the fundamental colours required by 

 Young's theory ; — the complementary of the orange is the 

 first green-blue ; the third yellow-green, of which the com- 

 plementary is the first violet ; and the third blue, having 

 as complementary the yellow placed between the first and 

 second vellow. The defects of the old colour circle are 

 discussed. — Measurements of the Brownian movements in 

 gases and the charge of particles in suspension : M. 

 de Brogrlie. From an ultramicroscopic study of the 

 •motion of a charged particle of tobacco smoke in an 

 electric field, followed by the application of the formulae 

 of Stokes and Einstein, the value for the charge e is 

 deduced as 4:;Xio-'°, agreeing well with the results 

 obtained bv different methods. — The lower harmonics : 

 G. Sizes and G. Massoi. — Kathodic projections :_ L. 

 Houilevigrue. It is known that a kathode placed in a 

 vacuum projects, besides corpuscles deviable by a magnet, 

 particles of itself. Since these are not appreciably deviated 

 by a magnetic field, it follows that these particles have 

 either a relatively large mass, a small electric charge, 

 or a high velocity. The experiments here recorded accord 



