262 



NA TURE 



[January 12, 1899 



the mutual gravitational attraction of two bodies whose mass 

 distributions are symmetrical with respect to the same axis, 

 deals with certain problems in the theory of Attraction which, 

 although fairly accessible to treatment, seem to have been over- 

 looked (some of the equations occur in Todhunter, " History 

 of the Theories of Attraction and Figure of the Earth," vol. ii. 

 p. 102). — A paper by Prof. Roe, on symmetric functions, con- 

 siders the matter from two standpoints. The first part deals 

 with the functions as a whole, and is mainly critical and his- 

 torical. Part ii. treats of the individual terms of a symmetric 

 function, together with their coefficients. Prof. Chessin applies 

 the theory («hich we have noted in the abstract of a paper 

 previously read by him) to the problem of three bodies w,, Wo, 

 /H3, viz. when the mass of one of them (w^) is infinitely small 

 compared with the masses w, and m„, while the eccentricity of 

 the orbits of /«, and iit„ is zero, so that these bodies move uni- 

 formly in concentric circles above their common centre of 

 gravity. Such is very nearly the case of a small ]ilanet in the 

 presence of the sun and Jupiter, and also very approximately 

 the case of satellites. — Prof. Lovett's contact transformations 

 of developable surfaces discusses the determination of the con- 

 tact transformations which leave invariant the partial differential 

 equation | /n, />.»j, . . ., /„« | = o (cf. Lie, Darboux and Mayer. 

 .Some of the results are complete generalisations of those of a 

 memoir of G. \'ivanti, liend. di Cin. Mat. di Palermo, vol. v. 

 1891). — Concerning a linear homogeneous group in C„,,., vari- 

 ables isomorphic to the general linear homogeneous group in 

 HI variables, is a paper which was read by Dr. L. E. Dickson 

 at the August meeting. It is chiefly concerned with continuous 

 groups, but its results are readily utilised for discontinuous 

 groups. An analogous isomorphism is discussed in a paper 

 presented recently to the London Mathematical Society. — A 

 second locus connected with a system of coaxial circles, by 

 Prof. T. F. Holgate, read at the same meeting, is a very in- 

 teresting extension of a paper, by the same author, which was 

 communicated to the Toronto meeting, November 1897. — Prof. 

 Emch, of Biel, Switzerland, communicates a note, entitled 

 "Reciprocal transformations of projective coordinates and the 

 theorems of Ceva and Menelaos." The note is illustrated with 

 diagrams. The author confines himself to the two above-named 

 theorems and their connection with certain transformations of 

 plane and space. The properties admit of multiplication, some 

 of which have been discussed by Rosace and Steiner. — The 

 "notes," as usual, contain aigood deal of information useful 

 to mathematical students. 



SOCIETIES AND ACADEMIES. 

 London. 



Royal Society, December 15, 1898. — "Note on the 

 Densities of ' Atmospheric Nitrogen,' Pure Nitrogen, and 

 Argon." By William Ramsay, F. R.S. 



It is concluded that the density of "atmospheric" nitrogen 

 is correctly given as the mean of the densities of the constituents, 

 taken in the proportion in which they occur. 



Chemical Society, Dec. 15, 1898. — Prof. Dewar, President, 

 in the chair. —The following papers were read. — The interaction 

 of ethylic sodiomalonate and mesityl oxide, by A. W. Crossley. 

 Mesityl oxide and ethylic sodiomalonate do not condense in 

 the exi)ecied manner, but the product on hydrolysis yields a 

 diabasic acid, C,6ll.^,04 melting at I48-I48""5 ; derivatives of 

 this acid are described. — The interaction of ethylic malonate 

 and acetylene tetrubromide in presence of sodium ethoxide, by 

 A. W. Crc:)ssley. Ethylic disodionialonate and acetylene tetra- 

 bromide react with evolution of acetylene and formation of 

 tribromethylene and tetrethylic acetylenetetr.acarboxylate. — 

 Derivatives of camphoric acid : Part iii., by F. S. Ivipping. A 

 number of comjiounds obtained from w-bromocamphoric acid 

 are described. — Synthesis of oj33-triniethylglutaric acid, by 

 W. H. Perkin, jun., and J. F. Thorpe. Ethylic sodio-o- 

 cyano-^;8-din>ethylglularale is obtained by the interaction of 

 ethylic cyanacet.ite, ethylic dimethylacrylale and sodium 

 ethoxide ; methylic iodide converts it into ethylic a-cyano-aj8/3- 

 Irimethylglutarate which on hydrolysis gives o/3/3-trimethyl - 

 glutarimide. This imide yields a/3/3-lrimethylglutaric acid, 

 COOH.CllMe.C.Me„.ClI..,.COOIl, when heated with hydro- 

 chloric acid. — Hydrolysis of methylic and ethylic -y-cyanoaceto- 

 acetates and their derivatives. Part i., by \V. F. Lawrence. 



NO. 1524, VOL. 59] 



Methylic 7-cyanodimethylacetoacetate is hydrolyscd by hydro- 

 chloric acid with formation of oo-dimethyl-/3-hydroxyghitaconic 

 acid, COOH.ClI:C(OII).CMe..COOH ; this, on reduction 

 with hydriodic acid, yields 00-dimethylglutaconic acid. 



Geological Society, December 21, 1898. — W. VVhitaker, 

 F.R.S., President, in the chair. — On a Megalosauroid jaw 

 from Rhastic beds near Bridgend, Glamorganshire, by E. T. 

 Newton, F.R.S. The specimen which forms the subject of this 

 communication was obtained by Mr. John David of Porthcawl, 

 and it has been presented to the Museum of Practical Geology. 

 It was derived from beds low down in the Rh;\.tic series, which 

 may eventually have to be included in the upper part of the 

 Keuper. The specimen does not admit of exact comparison 

 with Megalosaitrits, and it is named as a new species of 

 Zaiichdoii — a genus in which the author is also inclined to place 

 some forms described under the names of Palaeosaurus, 

 Cladyodon, Avalonia, and Pifrodon. — The torsion-structure of 

 the Dolomites, by Maria M. Ogilvie [Mrs. Gordon]. The paper 

 opens with a general account of the work of Richthofen, 

 Mojsisovics, Rothpletz, Salomon, Briigger, the author, and 

 others on the Dolomilic area of Southern Tyrol. It then gives 

 the results of a detailed survey recently made by the author of 

 the complicated stratigraphy of the rocks of the Groden Pass, 

 the Buchenstein Valley, and the massives of Sella and Sett Sass ; 

 together with the author's interpretation of these results, and her 

 application of that interpretation to the explanation of the Dolo- 

 mite region in general. The author conclmles that overthrusts 

 and faults of all types are far more common in the Dolomites 

 than has hitherto been supposed. The airangement of these 

 faults is typically a /o/S!OH-phenomenon, the result of the super- 

 position of a later upon an earlier strike. This later crust- 

 movement was of Middle Tertiary age, and one with the move- 

 ment which gave origin to the well-known Judicarian-Asta 

 phenomena. The youngest dykes (and also the granite-masses) 

 are of Middle Tertiary age, while the geographical position of 

 both is the natural effect of the crust-torsion itself. This crust- 

 torsion also fully explains the peculiar stratigraphical phenomena 

 in the Dolomite region, such as the present isolation of the 

 mountain-massives of dolomitic rock. After discussing in detail 

 the structure of various areas, the author applies her results 

 to the interpretation of the complexities of the Judicarian- 

 Asta region of the Dolomites in general, and also to the 

 explanation of the characteristic structural forms of the Alpine 

 system as a whole. 



Royal Microscopical Society, December 21, 1898.— Mr. 

 E. M. Nelson, President, in the chair. — The President exhibited 

 a new objective by Carl Zeiss, called a " Plankton-searcher," a 

 low power water immersion objective, designed for use in 

 examining living objects in water, the definition of which was 

 exceedingly sharp. Me also exhibited an erecting eye-piece 

 fitted with Porro's prisms, another new appliance produced by 

 the same firm, which would be found useful for dissecting and 

 other purposes. — Mr. Keith Lucas exhibited and described a 

 new model microscope, the design of which was to effect the 

 coarse and fine adjustments by means of a single slide, thereby 

 reducing the expensive work of planing. — The President directed 

 attention to some of the various types of binocular microscopes 

 that were exhibited : among those referred to were Ahrens' 

 binocular eye-piece, in which both tubes were equally inclined, 

 and a microscope by Murray and Heath, one tube only being 

 inclined, the other lying in the optical axis of the instrument, 

 the construction being similar to that of Xachct ; these two 

 instruments were exhibited by the Society. — There was a new 

 binocular dissecting microscope by Leitz, exhibited by Messrs. 

 Watson and Sons, consisting of two Briicke lenses fitted on a 

 bar by jointed attachments so that the distance between the 

 tubes could be adjusted to suit the eyes. This was likely to 

 prove valuable for examination of objects, or for dissection under 

 low power. — Attention w.as directed also to a form exhibited by 

 Carl Zeiss, made with Porro's prisms, giving an erect image : 

 this microsco|>e is provided with two objectives of equal power, 

 one for each tube, the stereoscopic effect being greater than that 

 obtained by a divided image from one objective.— .Messrs. Powell 

 and Lealand exhibited their high-power binocular prism >n con- 

 junction with a i/2o-inch apochromatic objective. — \ Mojinie's 

 portable binocular, a Nel-son model, Wcnhani's binocular with a 

 high power objective, a binocular microspectroscope, were ex- 

 hibited, besides various patterns of Stephenson and Wenham 

 binocular microscopes by Messrs. Chas. Baker, R. and J. Beck, 



