February 27, 1902] 



NA TURE 



407' 



That the surface of a solution of hydrogen peroxide undergoing 

 this decomposition is capable of discharging negative electrifica- 

 tion. (<■) That days on which sunlight decomposes hydrogen 

 peroxide most rapidly are the days on which the discharging 

 action is most pronounced. The author draws from these ex- 

 periments the conclusion that the decomposition of hydrogen 

 peroxide by light is a possible source of production of positive 

 and negative ions in the atmosphere. A detailed account is to 

 be found in the Phil. Mag., January. — Note on a method 

 for determining the concentration of hydrogen ions in solution, 

 by Mr. H. O. Jones and Mr. O. W. Richardson. The investi- 

 gation described was suggested by a series of observations by 

 Mr. Fenton and one of the authors. They showed that oxal- 

 acetic hydrazone decomposed in presence of water at ioo° C. 

 into pyruvic hydrazone and carbon dioxide ; but that in the 

 presence of hydrogen ions in sufficient concentration the 

 products were pyrazolone carboxylic acid and water. It was 

 suggested that these reactions might be explained by supposing 

 that the negative ion lost carbon dioxide on heating ; whereas 

 the undissociated molecule lost water. Hence the presence of 

 hydrogen ions by diminishing the concentration of the negative 

 ion would diminish the amount of carbon dioxide produced. 

 The experiments here described were undertaken with the view 

 of testing quantitatively the validity of the above hypothesis 

 and the value of the method for determining the concentration 

 of the hydrogen ions in a solution. The authors find that, in 

 the case where the ionisation due to the hydrazone itself is neg- 

 ligible compared with that of the acid used, the experimental 

 results agree with the theoretical conclusions. — The forma- 

 tion of dinitrophenoxazines, by Mr. J. C. Crocker. — When 

 picryl chloride reacts with orthoxyamido-compounds in the 

 presence of alkali, hydrochloric acid and nitrous acid are elimin- 

 ated, and condensation takes place to a dinitrophenoxazine. 

 Eikonogen, for instance, gave naphthodinitrophenoxazine 

 sodium sulphonate, which consists of minute bronze plates 

 solublejin water. — The interaction of thiocyanates, picryl chloride 

 and alcohols, by Mr. J. C. Crocker. When picryl chloride acts 

 on thiocyanate in ab.solute alcohol solution, a yellow crystalline 

 body is obtained. It melts at 138°, contains an ethoxy-group, 

 two picryl groups and a sulphur atom. On hydrolysis it gives 

 picramide. Hydrochloric acid is set free in the reaction. — 

 Oxidation of glucosone to trioxybutyric acid, by Mr. R. S. 

 Morreli. Glucosone, prepared from glucose by the action of 

 hydrogen peroxide in the presence of ferrous sulphate, on oxida- 

 tion with bromine in aqueous solution yielded trioxybutyric acid. 

 The identity of the trioxybutyric acid was established by com- 

 paring its calcium and lead salts with those obtained from the 

 trioxybutyric acid which is formed when erythrite is oxidised 

 by nitric acid, also by the reduction of the calcium salt by 

 hydriodic acid and phosphorus to normal butyric acid. — 

 Note on the reduction of a ternary quantic to a symmetrical 

 determinant, by Dr. A. C. Dixon. 



Edinburgh. 

 Royal Society, January 20. — Lord Kelvin in the chair. — 

 Lord Kelvin, in a paper on the specification of stress and strain 

 in the mathematical theory of elasticity, showed how a perfectly 

 symmetrical system applicable to all kinds of strains and not 

 merely to very small strains could be developed by considering the 

 elongations of the edges of a tetrahedron and the related stresses 

 (see Phil. Mag. for January, 1902). The method for bringing 

 this system into relation with the ordinary system for infini- 

 tesimal strains was indicated, and the discussion was greatly 

 facilitated by the use of models. — Dr. W. Brodie Brodie read a 

 paper on the condition of the iron in the spleen, and detailed 

 some of the results of an investigation into the histological and 

 chemical position of the iron in this organ. By the usS of 

 microchemical methods, the metal was found contained in cells 

 and also in bodies not of a cellular nature. Three varieties of 

 iron-containing elements were described as belonging to the 

 latter class. Three proteid bodies containing iron which had 

 been obtained by means of purely chemical methods were also 

 described. — Lord Kelvin cummunicated a paper on the molecular 

 dynamics of a crystal, discussing in particular {a) stable and un- 

 stable homogeneous assemblages, (b) deviation from homo- 

 geneousness in surface layers, (i) tensile strength, (d) cleavage. 

 The whole discussion was based upon the Boscovich view that 

 the action between neighbouring atoms is attractive or repulsive 

 according to their distance apart. The forces acting upon a 

 given alum will depend, not only upon the nearest neighbours, 



NO. 1687, VOL. 65] 



but also upon those at greater distances. Taking simple con- 

 figurations, Lord Kelvin showedihow during the condensation of 

 an assemblage of atoms configurations of instability might arise, 

 and how the group originally monatomic might either assume a 

 new stable configuration of diflerent density or break up into a 

 diatomic configuration of greater stability. By a process of 

 successive approximations, the final positions of the end particles 

 of a one-dimensional row of particles acting on one another, 

 according to an assumed Boscovichian law, were calculated. 

 Reckoning from the end, the distances between the successive 

 pairs of contiguous particles were alternately greater and less 

 than the ultimately constant distance to which they converged 

 as we passed further and further from the end. After the first 

 nine or ten particles, the arrangement became uniform. — A com- 

 munication by Dr. Thomas Muir, on the theory of Jacobians in 

 the historical order of development up to 1841, was also 

 received. 



Paris. 

 Academy of Sciences, February 17.— M. Bouquet de la 

 Grye in the chair.— A study of the conditions to be realised in 

 the execution of negatives in order to obtain homogeneity and 

 the maximum of exactitude in the determination of the coordi- 

 nates of stellar images. Formula; for evaluating the influence 

 of the whole of the causes of error which affect the results, by 

 M. Lcewy. The rectilinear coordinates of photographic stellar 

 images are liable to two distinct classes of errors, the first being 

 due to the unequal sensibility of the gelatine layer and to the ir- 

 regular deformations which it undergoes during development, 

 and the second having its origin in the subsequent measuring 

 operations. A careful analysis of the relative magnitudes of these 

 two causes of error in the case of stars of difterent orders of 

 magnitude is given and a formula worked out for the probable 

 error, from which it is hoped that a still higher accuracy may 

 yet be obtained by the photographic method. — An apparatus for 

 measuring differences of longitude with the aid of photography, 

 by M. G. Lippmann. The essential part of the apparatus con- 

 sists of a transparent mirror inclined at an angle to a mercury 

 bath, and has already been described as a means of measuring 

 photographically small zenithal distances. It is equally applic- 

 able to the measurement of small differences of longitude.— Th 

 action of potassium hydride on ethyl iodide and methyl chloride- 

 New methods of preparation of ethane and methane, by M. 

 Henri Moissan. Potassium hydride heated in a sealed tube vvith 

 ethyl iodide at about 200° forms ethane and potassium hydride. 

 The reaction is not complete, but is perfectly free from bye- 

 products. The ethane is separated from the hydrogen by means 

 of liquid air, and from the ethyl iodide in excess by fractional 

 distillation and subsequent washing with alcohol and water. The 

 gas was proved by analysis to be perfectly pure. The reaction with 

 methyl chloride is analogous, pure methane being produced.— 

 Study of the vineyards of high yield in central France, by M. A. 

 Miintz. It isshown to be moreadvant.ageous to moderate production 

 in order to obtain a superior wine than to exaggerate the yield by 

 methods giving enormous quantities of wine of feeble quality. — 

 The estimation of sugars in the blood, by MM. R. Lepine and 

 Boulud. A comparison of the polarimetric and copper reduction 

 methods.— The mechanical action of gelatine on solid substances 

 and particularly on glass, by M. L. Cailletet. Gelatine on 

 drying exercises a very energetic mechanical action on the sur- 

 faces to which it adheres. On surfaces of glass, polished 

 marble, Iceland spar and fluorspar, pieces are broken off, and a 

 cylindrical tube of thin glass may be broken by means of the 

 action of a small quantity of drying glue. — M. Charles Andre 

 was elected a correspondant for the section of astronomy in 

 the place of the late Dr. Gould.— Perturbations of the major 

 axis of small planets, by M. Jean Mascart.— On quasi-entire 

 functions, by M. Edmond Maillet. — On a class of partial differ- 

 ential equations integrable by successive approximations, by 

 M. R. d'Adhemar. — On some transformations of contact, by 

 M. W. de Tannenberg. — On a form of electric thermometer, by 

 M. Georges Meslin. In certain cases the rapidity with which 

 thermocouples follow the temperature changes of the medium 

 in which they are placed is disadvantageous. The author 

 therefore proposes to use the variation of electromotive force of 

 a Latimer Clark cell with temperature as a thermometer, the 

 thermal lag of which is very pronounced compared with a 

 thermocouple. — Researches on ionised gases, by M. P. Langevin. 

 A development of the theory of ionised gases of J. J. Thomson, 

 together with an experimental confirmation of the theoretical 

 1 deductions.— On the transparency of liquid conductors for the 



