June 13, 1895J 



NA TURE 



167 



Paris. 

 Academy of Sciences, June 4. — M. Lnu-wy in the chair. — 

 Ndlicc on the works of M. Neiniiann, by .M. J. Bertrand. 

 Kranz Nt-iimann, correspondent of the tieoiuetry Section, died 

 .il Koni^jsberg on May 23 last. He will be chiefly remembered 

 by his great memoir "On the theor)- of undulations," in 

 which he considers luminous vibrations as occurrini; in the plane 

 of polarisation. His great mathematical ability was especially 

 shown by the general formulae in which he expressed the results 

 of Faraday's discoveries and I,enz's rules. — Volume of salts in 

 their aqueous solutions, by M. Lecoq de Boisbaudran. The 

 author compares the dilatometer and pyknometer methods, and 

 describes a special form of dilatometer used in this work. — A 

 contribution to the study of the acetylcyanacetic esters of the 

 Ijenerai formula. 



C.IL.„n-CO.CH 



,„/■ 



CN 



C,.1I,.„+,.CII :COH . (11 



CO.R 



by M. A. Ilaller. — A projected Swedish exploration of Tierra 

 del Kuego, by M. Daubrce. The .Swedish government is about 

 to send out an expedition of three persons to explore the un- 

 known parts of Tierra del Fuego, and the .Argentine Govern- 

 ment will assist by conveying the members of the exploring party 

 to their destination and finding attendants. M.\I. Xordenskiold, 

 I)usen, and Ohiin will arrive at Buenos .\yres in .September, 

 and hope, during the Antarctic summer, to explore those parts 

 of the islanil nnvisited by the French expedition of 1882-1883. 

 They aim ]Mrlicularly at gathering material for a comparison of 

 the southern island with Northern Kurope ; for instance, the 

 quaternary rocks of Tierra del Fuego will be compared 

 with rocks of the same age in the boreal continents. 

 — Report on the project of a balloon expedition to the 

 Polar regions, by M. J. .'\. Andree (Committee : MM. Faye, 

 Daubrce, Blanchard). It is reported that the conditions for 

 the success of such an expedition have been fully considered, 

 the funds necessary have been raised, and the expedition will 

 set out from Spitzbergeii in July of the coming year. The con- 

 ditions formulate<l by M. .Andree are: (I) The balloon must 

 have an ascensional power suHicient to carry three persons, all 

 the necessary instruments, food for lour months, arms, a boat 

 transformable into a sledge, and the ballast, in all about 3000 

 kilograms. (2) The balloon must have the cpialily of impermea- 

 bility to such an extent that it can remain thirty days in the air. 

 (3) It must be to a certain extent dirigable. — .Memoirs pre- 

 sented : By M. A.' Lucas, on the centrifugal and centripetal 

 forces and on a new value of a; ; by M. Bonnal, an alcoholi- 

 meter allowing the simultaneous estimation of alcohol and 

 extract in wines. — Observations of Charlois' planet BX, made 

 with the Coude equatorial at Algiers Observatory, by .MM. 

 RamlKiud and .Sy. — On the movement of a plane figure in its 

 plane, by M. \. Pellet. -On a category of groups of substitutions 

 a.ssociateil with groups of which the order equals the degree, by M. 

 R. Levavas.seur. — On thedensity of helium (a letter from M. Cleve 

 to M. Berthelot). (See Notes.)— On the reduction of nitrous oxide 

 by metals in presence of water, by M.M. I'.aul .Sabatier and J. B. 

 Senderens. The results fully confirm those formerly obtained. 

 Dissolveil nitrous oxide is reduced to the state of nitrogen 

 by magnesium, zinc, iron, and even cadmium, with the 

 simultaneous formation of a little ammonia. — Heal of forma- 

 tion of s'odium acetylide, by .\I. de Forcrand. —On phthalyl 

 chloride and phthalide, by .M. Paul Rivals.— Conducti- 

 bilily of some i8-ketonic esters, by M. J. Guinchant. The 

 siHliuni salts of the cyanomelhinu acids behave ijuite normally 

 with regard to conductibilily. These acids, as well as acetyl- 

 acetone. obey Ostwalil's law (K = const.). as far as can be expected 

 with coinpoumls containing an acid group and an ether function. 

 Their chemical affinity deduced from thermochemical data agrees 

 well with that obtained from their conductibilities. The values 

 of K for homologous acids diminish .as the molecular weight 

 increases. — ICstimation of volatile acids in wines, by M. E. 

 Burcker. Considerations on the chemical phenomena of ossifi- 

 cation, by M. C. Chabrie.— On the fl.ira of the coal deposits of 

 Asia Minor, and the jiresence in this flora of the genus Phyllo- 

 Ihciit. by M. R. Zeiller. — On the chlorosis of .\merican vines 

 and its treatment by sulphuric acid, by M.M. (;a,stine and 

 Degrully. The authors find treatment by ferrous sulphate and 



NO. 1337, VOL. 52] 



by sulphuric acid to yield identical results ; it is concluded that 

 the sulphuric acid is the active agent in overcoming chlorosis. — 

 Oii/iiim albican!, a general pathogenic agent. Pathi^eny of 

 morbid tlisorders. by MM. Charrin and Ostrowsky. In conclu- 

 sion, the study of the general disexse which determines inocula- 

 tion by OrJiiim alhUaiis reveals a series of proces.ses peculiar to 

 this fungus. Comparing these processes with those due to 

 bacteria, some analogies, but more differences, are ob.served. 



BF.Ri.rs. 



Physiological Society, May 3. —Prof. H. Munk, President, 

 in the chair. — After the President had dwelt on the loss physio- 

 logy had sufl'ered by the death of Prof. Ludwig, I'rof. I. Munk 

 spoke on Kjeldahl's method for determining nitrogen in organic 

 substances as C(jmpared with Dumas' method. The former has 

 largely supplanted the latter ow ing to the greater ease with which 

 it may be carried out, but some chemists have found it less 

 accurate than thai of Dumas, notably when applied to casein. 

 The speaker had recently repeated the analysis, and found the 

 above statement confirmed as long as he used oxide of coppei 

 in Kjeldahl's process. But when he used oxide of mercur\' 

 (Wilfarth) or polassimii bichromate (Kriiger), the two methods 

 gave identical resvdts for the nitrogen. He had also foimil 

 Kjeldahl's method applicable to nitrogenous compounds with 

 clo-sed rings, such as pyridin, chinolin, ..Vc. Prof, (jad developed 

 F'ick's hypothesis as to the two-fold nature of the chemical 

 processes taking place in a contracting muscle, a hypothesis to 

 which he gave his support on the ba.sis of his experiments made 

 together with Heymans (see Naturk, vol. xl. p. 288), on the 

 influence of tenq")erature on nuiscular contraction. He described 

 several experiments on the production of heal in muscles con- 

 tracting isotonically and isometrically, which can be most readily 

 I explained on the basis of Fick's hypothesis of two mutually 



interfering chemical jjrocesses. 

 I M<ay 17. — Prof H. Munk, President, in the chair. — Dr. 

 [ W. Cowl spoke on the action of diaphragms in microscopes, and 

 , explained a general improvement he hafl obtained by applying 

 I an iris-diaphragm to the ocular, capable of regrdation from the 

 outside. — Dr. Thierfelder gave an account of experiments made 

 with Dr. \utan tin guinea-pigs. 



Physical Society, May 10. — Prof, von Bezold, President, 

 in the chair. — .\fter election of officers. Prof. Konig spoke on 

 ! experiments made in conjunction with Dr. Rubens on the dis- 

 ; tributiim of energy in the spectrum of a triplex burner. The 

 methods employed made it possible to measure the energy by 

 means of a bolometer between W.L. 800^ to W. L. 420 ji. 

 and at the same time to measure the intensity of the light at 

 the same part of the spectrum by means of a Limimer photo- 

 meter. He dealt in great detail with the correction which is 

 i necessary on account of the fact that diffused light acts on the 

 bolometer in addition to that of each given wave-length. The 

 curve of energy thus obtained was so steep that it could only be 

 recoriled by logarithms ; the energy of the extreme red was 

 more than a ihousanit times as great .as that of the blue. By 

 comparing the relative intensities of the rays of a normal amyl- 

 acetate flame w ith that of the above burner, the distribution of 

 energy in the amylacetate flame was deduced by calculation, and 

 in this case also the curve w\as very steep ; the energy of the red 

 end being 300 times that of the blue. "The curve for the spec- 

 trimi of the cloudless sky ascended from the red towards the 

 blue end, whereas it was nearly horizontal for the light from a 

 cloud. — Prof. Neesen exhibited two automatic mercurial air- 

 pumps. 



May 24. — Prof, du Bois Reymond, President, in the chair. — 

 Prof. Neesen described an automatic mercurial valve added to 

 his automatic pumps. — Prof, von Bezold spoke on a theory of 

 terrestrial magnetism, based on the constniction of the i.sonomals 

 of terrestrial magnetic ]>otentials. He explained the methods 

 by which he had calculated the isonomals, anil iliscussed the 

 results observable on a chart of the s.ame for the year 1880. 

 The mean values of magnetic potential are sinqile functions of 

 geographical latitude, and the isonomals have both their poles in 

 the southern hemisphere. The determination of the potential 

 and the construction of the lines of equilibrium is far simpler 

 by Prof, von Bezold's method than by the employment of 

 Gaus.s's formuUe, and w ill make it possible to attack a whole 

 series of imi>ortant problems concerning terrestrial magnetism. 

 ] As soon as isonomal charts have been constructed for different 

 J periods it will be possible to draw conclusions a-s to the causes of 

 I magnetic disturbances. 



