January 26, 1905] 



NA TURE 



311 



appear fortuitously at rare intervals, and have no con- 

 tinuous existence either in time or space. If the sether 

 were a granular medium in normal piling, it would be 

 ^eolotropic with eighteen elastic constants, and the velocity 

 of propagation of waves of high frequency would be much 

 greater than that of waves of low frequency. Light 

 transmitted from distant stars would consist largely of 

 mirages and coloured spectra. — On a class of expansions 

 in oscillating functions : Prof. A. C. Dixon. The paper 

 deals with expansions of the kind discussed by Liouville 

 and Sturm in w-hich arbitrary functions are expanded in 

 series of special functions which satisfy differential equa- 

 tions of a certain type. These expansions are used fre- 

 quently in applications of mathematics to physics. The 

 object of the paper is to give a rigorous proof of the 

 possibility of such expansions in the case of functions 

 which are analytic throughout the proposed range of 

 validity of the expansions. — Generational relations for the 

 abstract group simply isomorphic with the group 

 LF[2,/)"] : Dr. W. H. Bussey. — On alternants and con- 

 tinuous groups ; Dr. H. F. Baker. The paper is occupied 

 with the proof of that fundamental theorem of non-com- 

 mutative algebra which is usually written in the form 

 e*eB = ec^ where a and B are non-commutative quantities, 

 and c is a series of alternants of a and b. The proof is 

 derived from a property of a matrix called the E-matrix, 

 which involves the structure constants, and one set of the 

 canonical variables, of the parameter group. This property 

 is established independently of the theory of continuous 

 groups. It is proved, further, that every alternant of 

 E-matrices is an E-matri.\, and thence is obtained a general 

 expression for the equations of the first parameter group. 

 — A generalisation of the Legendre polynomial : H. 

 Bateman. — Isogonal transformation and the diameter 

 transformation : H. L. Trachtenberg. 



Royal Astronomical Society, laruary 13. — Prof. H H. 

 Turner, president, in the chair. — The eclipse of Agathocles 

 in the year — 3oq-: Prof. Newcomb. The author considered 

 that this eclipse had been identified by Celoria with an eclipse 

 said by Cleomedes to have been total in the Hellespont. 

 Assuming this to be the case, it would be necessary to 

 make a diminution of i"-5 in the secular acceleration. — 

 The longitude of the moon's perigee : Mr. Covvell. — 

 Magnetic storms and associated sun-spots : Rev. A. L. 

 Cortie. Discussing Mr. Maunder's paper (read at the 

 November, 1904, meeting), Father Cortie considered it 

 was still possible to consider sun-spot phenomena and 

 magnetic storms as produced by some common cause, and 

 brought forward evidence from the Stonyhurst observations 

 which he thought conflicted with some of Mr. Maunder's 

 conclusions. — h paper on the same subject : Prof. 

 Schuster. From Mr. Maunder's statistics, which Prof. 

 Schuster discussed, it appeared that in some form or other 

 magnetic storms recur at intervals apparently identical 

 with that of the revolution of sun-spot zones. The author 

 was unable, however, to accept iVIr. Maunder's explan- 

 ation of the cause of the storms, which he considered as 

 of terrestrial origin, the earth's diurnal rotation being 

 the real source of the energy. The energy thus drawn 

 away from the earth would tend to diminish its velocity 

 of rotation, but in a million years this diminution would 

 not amount to more than a second a year. Without form- 

 ing a definite theory on the subject. Prof. Schuster 

 suggested that there is some solar effect, propagated in 

 straight lines, which may increase the electric conductivity 

 of the earth's atmosphere, and thus set a magnetic storm 

 going without supplying its energy. The author concluded 

 that Mr. Maunder had shown the urgent importance of 

 further investigation, but that the facts have become more 

 difficult to understand and explain. After a discussion, 

 followed by a reply from Mr. Maunder, the meeting 

 adjourned, many other papers being taken as read. 



Paris. 

 Academy of Sciences, January 16. — M. Tioo-t in the 

 chair. — On the generalisation of an elementary theorem 

 of geometry : H. Poincare. The theorem that the sum 

 of the angles of a plane triangle is equal to two right 

 angles is extended to the case of the tetrahedron. — On 

 some theorems relating to algebraic surfaces of linear 



NO. 1839. VOL. 71] 



connection greater than unity : Emile Picard. — On 

 some physical constants of calcium and on calcium 

 amalgam : H. Moissan and M. Chavanne. — On the 



3-methyl-€-aIkylcyclohexanones and Ihe corresponding 

 alcohols, homologues of menthone and menthol : A. 

 Haller. /3-Methylcyclohexanone, which can be prepared 

 either by the decomposition of pulegone or from metacresol 

 by Sabatier and Senderens's method, is treated with 

 sodium amide and the alkyl iodide. A mixture of various 

 alkyl derivatives is obtained which up to the present has 

 not been completely separated into its constituents. — On 

 a synthesis of menthone and menthol : A. Haller and C. 

 Martine. Methylcyclohexanone is treated successively 

 with sodium amide and isopropyl iodide, the mass treated 

 with water, extracted with ether, and the latter solution 

 fractionated in a vacuum. The physical properties of the 

 menthone obtained, as well as those of its oxime, semi- 

 carbazone, and other derivatives show that the synthetical 

 is identical with the natural product. — Observations of the 

 Borrelly comet (1904 e) made at the Observatory of Paris 

 with the 305 cm. equatorial : G. Bigourdan. — On irregular 

 algebraic surfaces : Federigo Enriques. — On some points in 

 the theory of numbers : Georges Remoundos. — On equations 

 of the parabolic type : S. Bernstein. — On fluorescence : 

 C. Camichel. The author has repeated some experiments 

 of J. Burke on fluorescence with some additional pre- 

 cautions. His conclusion, which is opposed to that of 

 Burke, is that the coefficient of absorption of uranium 

 glass for the radiations which it emits during fluorescence 

 is the same whether the fluorescence be excited or not. — 

 Some combinations of samarium chloride with ammonia : 

 C. Matignon and R. Trannoy. Samarium chloride 

 forms eight different compounds with gaseous ammonia. 

 The range of temperatures between which each of these 

 compounds can exist, together with the heats of dissoci- 

 ation, were determined. — On a colloidal hydrate of iron 

 obtained by electrodialysis and on some of its properties ; 

 J. Tribot and H. Chretien. A solution of ferric hydrate 

 in ferric chloride was placed in an ordinary Graham 

 dialyser, and the amount of chlorine remaining in the 

 solution determined at different intervals of time, in the 

 first place on simple dialysis, and afterwards when a 

 current of i ampere was passed through the solution. 

 In the latter case the chlorine was more quickly and more 

 completely removed ; the theory of the two cases is given 

 in detail, and the theoretical and actual results compared. 

 — On an isomeride of trichloracetone : G. Perrier and 

 E. Prost. .Aluminium chloride is allowed to act upon 

 alcohol in carbon bisulphide solution, and chloral is added. 

 A liquid product possessing the composition and molecular 

 weight of trichloracetone is obtained. The reactions, how- 

 ever, are quite different from this latter substance, and 



CCI3 



I 

 the formula HC — » is provisionally proposed. — The migra - 



CH3/ 

 tion of the ethylene linkage in unsaturated acyclic acids : 

 E. E. Blaise and A. Luttringer. The migration of the 

 ethylene linkage has been studied in the case of six 

 alkylacrylic acids and normal a/3-hexenic acid. It appears 

 to move into the longest chain, giving either an isomeric 

 acid or a 7-lactone. — On the combination of natural leucine 

 with carbamic acid : M. Hugounenq and Albert Morel. 

 — On a new method of synthesising saturated ketones by 

 the method of catalytic reduction : M. Darzens. It is 

 shown that in applying the reaction of .Sabatier and 

 Senderens the temperature at which the reduced nickel 

 is reduced is of equal importance with the tempera- 

 ture at which the reduction is carried out. If the nickel 

 is prepared at 245° C. to 250° C, and the reduction is 

 carried out at 180° C. to 190° C, unsaturated ketones can 

 be readily reduced to the corresponding saturated com- 

 pounds without the formation of considerable amounts of 

 secondary alcohols as by-products. The reaction has been 

 applied to mesityl oxide, methylhexanone, and methyl- 

 heptenone. — Observations on the Borrelly cojnet (1904 e) 

 made at the Observatory of Besan^on : P. Chofardet. — 

 Observations of the Borrelly comet (i' 1904) made at the 

 Observatory of Algiers with the 31-8 cm. equatorial ; 



