February i, 1906] 



NA TURE 



335 



Paris. 

 Academy of Sciences, January 15. — M. H. Poincare in 

 the chair. — The landing of aeroplanes : Bouquet do la 

 Grye. A plan of arresting an aeroplane, and capable of 

 keeping it horizontal during its descent, is described. It 

 has been found to work in experiments on the small scale. 

 — The n-rays : M. Mascart (see p. 325). — The influence 

 of the reaction of the medium on the activity of amylase 

 and on the composition of saccharified starch : L. 

 Maquenne and Eug. Roux. The effect of the acidity 

 in- alkalinity of the solution on the hydrolysis of starch 

 by malt has been recognised by other workers, without, 

 however, the effect being quantitatively determined. The 

 author shows that phmolphthalein is an unsuitable in- 

 dicator to use for these experiments, methyl orange being 

 better. He has found that for a rapid hydrolysis it is 

 first necessary to neutralise the alkali of the starch, then 

 to add to the malt a quantity of sulphuric acid equal to 

 about 0-4 of that which would be required to neutralise 

 it completely. Not only can the rate of hydrolysis be 

 greatly increased by this treatment, but the proportion of 

 maltose formed is also raised about 10 per cent, to 15 per 

 cent. — Observations on the subject of the group C(OH) of 

 the tertiary alcohols : Louis Henry. Tertiary butyl 

 alcohol is converted by aqueous fuming hydrochloric acid 

 into the corresponding chloride with great ease ; by the 

 substitution of the hydrogen atoms of the methyl groups 

 by other elements the action of the hydrochloric acid is 

 modified, the velocity of the reaction and amount of the 

 ester formed being reduced, or the action altogether pre- 

 vented. In the present paper the effects produced by the 

 introduction of chlorine, cyanogen, and oxvgen are dis- 

 cussed. — Some integrals of partial differential equations : 

 E. Goursat. — A family of conjugated networks with the 

 same- congruence : E. Merlin. — The impossibility of nega- 

 tive waves of shock in gases : Gyozo Zemplen. A reply to 

 the criticisms of P. Duhem on a former note on the same 

 subject. — The conditions of establishment and application 

 of progressive damping for the oscillations of road vehicles : 

 A. Krebs. It is shown by a theoretical analysis of the 

 problem that the friction of ordinary carriage springs 

 ceases to be efficient when the sudden change of level is 

 more than 2 cm. A new arrangement is described which 

 satisfies the theoretical conditions for greater oscillations, 

 and which has been found to work well in practice. — 

 Photographic experiments on the action of the u-ravs on 

 an oscillating spark : C. Gutton. If the n-rays are allowed 

 to fall on the primary spark of a Hertzian oscillator, the 

 secondary spark diminishes. The present paper deals with 

 the photographic registration of this effect. — The density 

 of ice : A. Leduc. About 108 grams of water were 

 frozen in each of the author's experiments. Well 

 boiled distilled water gave a density of 09172, but it was 

 clear that this number was too small, since in the upper 

 part of the density flask small strings of separated air 

 bubbles were visible. By repeatedly melting and freezing 

 in a vacuum, the density was raised to 09176, and even 

 in this case there was some evidence of traces of dissolved 

 air. It is pointed out that the usual method of analysing 

 the gases dissolved by water must be inexact, since all gas 

 is not expelled by boiling. — The distribution of electric 

 currents in a network : I. Revilliod. — A parhvdric valve : 

 J. de Rohan Chabot. A description of a new form of 

 valve for preventing the return of water into the vacuum 

 of a filter pump. — Correction to a note on the saline oxide 

 of nickel : H. Baubigny. — The silicide of copper, and a 

 new mode of formation of silicon soluble in hydrofluoric 

 acid : Paul Lebeau. When the amount of silicon in a 

 copper silicon mixture is raised above 10 per cent., a 

 metallographic examination shows the presence of free 

 silicon. — A silicide of thorium : O. Honigschmid. This 

 has been prepared by heating together a mixture of 

 aluminium, potassium fluosilicate, and the double fluoride 

 of thorium and potassium ; the excess of aluminium is re- 

 moved by treatment with potash solutions. The compound 

 isolated, the chemical and physical properties of which are 

 given, has the composition ThSi.,. — The diazo-derivatives 

 of the diamines : Leo Vignon. — The estimation of carbon 

 monoxide in air by iodic anhydride : Albert Levy and 

 A. Pecoul. Although acetylene reacts with iodic anhy- 



NO. 1892, VOL. JT,~\ 



dride, it does not interfere with the estimation of minute 

 amounts of carbon monoxide in air, since a mixture of 

 1 part of acetylene in 10,000 parts of air gives no iodine. — 

 The estimation of small quantities of chloroform in air 

 and in blood or in aqueous solution : Maurice Nicloux. 

 A combination of the methods of Dumas (the action of 

 alcoholic potash on chloroform) and Mohr (chlorine titra- 

 tion in presence of a chromate). — The combustion of 

 acetylene by oxygen : Paul Mauricheau-Beaupre. An 

 examination of the products of combustion of the oxv- 

 acetylenic blow-pipe flame showed that oxides of nitrogen 

 and ozone were present, but no trace of carbon monoxTde. 

 — The direct proportionality between the cryoscopic point 

 of a mineral water of the bicarbonate class and the com- 

 position of this water expressed as anhydrous mono- 

 carbonate : Lucien Graux. The half-bound carbonic acid 

 is without effect on the freezing point. — Mixed crystal-, of 

 alkaline nitrates: Fred. Wallerant. — The alkaline rocks 

 in the neighbourhood of Evisa, Corsica : M. Deprat. — 

 The yield of urine : Henri Lamy and Andre Mayer. — 

 The vitelline of the egg : L. Hugounenq. -Now researi hes 

 on the oxidations produced by animal tissues in the 

 presence of ferrous salts : F. Battelli and Mile. L. Stern. 

 Examples of the analogy between the oxidations produced 

 by hydrogen peroxide in presence of ferrous sulphate and 

 by animal extracts in presence of the same salt. — The 

 anomalous behaviour of the proteolysis produced by 

 papaine : C. Delezenne, 11. Mouton, and F. Pozerski. 

 — The whitening of wheaten flour : E. Fleurent. The 

 oxides of nitrogen are more favourable than ozone, the 

 latter giving an objectionable smell to the flour. — Geology 

 of the Peloponnesus : Ph. Negris. — An ancient volcanic 

 chain to the X.W. of the Puys chain : Ph. Glangeaud. — 

 Magnetic observations made at Sfax, Tunis, on the 

 occasion of the total eclipse of the sun of August 30, 1905 : 

 M. Dehalu. 



January 22. — M. H. Poincare in the chair. — The boiling 

 of osmium, ruthenium, platinum, palladium, iridium, .111.! 

 rhodium : Henri Moissan (see p. 325). — The origin of 

 the idea of solid solutions : Lecoq de Boisbaudran. A 

 claim for priority in the idea of solid solution. — Glycuronic 

 acid in the blood corpuscles : R. Lepine and M. Boulud. 

 The authors point out the liability of changes in the glycu- 

 ronic acid contents of the blood after it has left the blood- 

 vessel, and the precautions necessary to avoid such change. 

 — A theorem relating to the second differentials of the 

 potential of an attracting volume : A. Korn. — Elliptical 

 polarisation produced by mixed liquids : J. Chaudier. — 

 Some new magneto-optical properties of colloidal solutions 

 of oxide of iron : A. Cotton and H. Mouton. — The 

 kathodic phosphorescence of europium : G. Urbain. 

 Certain differences in the spectra observed might be in- 

 terpreted as being due to two elements in europium, or 

 possibly to purely physical causes independent of the 

 elementary complexity. Further experiments will be made 

 to elucidate this point. — Mixtures of antimonv and 

 tellurium, antimony and selenium, and the cryoscopic 

 constant of antimony : H. Pelabon. — Methoxvtrichloro- 

 pentanol 1:5:4 and a-trichloromethyltetrahydrofurfurane : 

 J. L. Hamonet. — Acetylenic amides and nitrites : Ch. 

 Moureu and I. Lazennec. A general method for pre- 

 paring the amide R — C = C — CONH, and the correspond- 

 ing nitriles is given. — Glycidic condensation of the alde- 

 hydes with a-chloropropionic ester : Georges Darzens. — 

 The acyclic vinyl and /3-chloroethyl ketones : E. E. Blaise 

 and M. Maire. — A crystalline modification stable in two 

 intervals of temperature : Fred. Wallerant. — The influence 

 of the colouring matters in a mother liquid on the form 

 of the crystals deposited : P. Gaubert. During their 

 growth, crystals of phthalic acid can absorb a certain 

 quantity of foreign material which exercises an influence 

 on their form and size. The different faces are not pene- 

 trated by the foreign substance with the same facility. 

 The actual amounts of the colouring matters included were 

 small, 1 170th for methylene blue and less for other sub- 

 stances. — The mechanism of the fall of certain terminal 

 buds : A. Tison. — A new genus of fungus from British 

 East Africa : P. Hariot and X. Patouillard. — The vari- 

 ations of phosphoric acid and nitrogen in the juices of the 

 leaves of certain plants : G. Andre. In an annual plant, a 



