December 5, 1907] 



NA TURE 



119 



chequers which they form take the appropriate shape at 

 each point of the field. The metliod can only be applied 

 in cert, n types of symmetry, as where V is constant 

 along eacli line of one or other of the following families 

 of lines : — (i) parallel straight lines ; (2) circles with their 

 centres on a common axis and their planes normal to 

 this axis ; (3) radii from a point ; (4) the normals common 

 to the two surfaces of a thin shell of any shape ; and (5) a 

 certain family of screw-threads. It is doubtful whether 

 there are any other possible types. Within these five types 

 of symmetry the freehand method far surpasses analytical 

 methods in its adaptability to boundaries and boundary 

 conditions of almost any shape which can be drawn on 

 paper. It can no doubt be extended to deal with con- 

 ductivity which depends on position, on the potential, or 

 on the force. — The lateral vibration of bars supported at 

 two points with one end overhanging : Dr. J. Morrow. 

 When a bar, supported at one end and at some other 

 point in its length, vibrates under its own mass only, the 

 expression from which the frequency can be determined is 

 of considerable complexity. When different values are 

 assumed for the ratio of the overhanging length to the 

 distance between the supports, the expression reduces 

 to a customary form with a coefficient depending on this 

 ratio. This coefficient is given here to six figures for 

 different ratios from zero to unity. The results show that 

 Dunkerley's approximate values cannot be relied on to 

 more than two figures, and that Chree's simple formula 

 gives remarkable accuracy for cases in which the over- 

 hanging length is less than half the span. 



Zoological Society, Nnvember 12.— Dr. F. DuCane 

 Godman, F.R.S., vice-president, in the chair. — Mammals 

 collected at Beira by Mr. C. H. B. Grant, being No. 8 

 of the series of papers on the Rudd exploration of South 

 Africa : Oldfield Thomas and R. C. Wroughton. 

 Twenty-eight species were included in the collection, re- 

 presented by 127 specimens, all, as before, presented to 

 the National Museum by .Mr. C. D. Rudd. The region 

 not having been previously worked, the series was of 

 much interest from a geographical point of view. — The 

 feeding of serpents in captivity ; Dr. P. C. Mitchell and 

 R. I. Pocock. The different habits of python-like, non- 

 poisonous and poisonous colubrine and viperine snakes 

 were described, and it was stated that no evidence was 

 found as to the existence of a specific fear of snakes in 

 the case of any vertebrates except Primates, and that, 

 amongst Primates, lemurs were distinguished from true 

 monkeys by their complete indifference to snakes. — Descrip- 

 tions of some new loricariid fishes, viz. five species of 

 Plecostomus and an Otocinclus from eastern Brazil, and 

 two species of .Arges from Colombia : C. Tate Re^ran. — 

 Notes on Mayer's pigeon : Lieut. -Colonel X. Manders. 

 The habits of this nearly extinct bird were described. — 

 Observations on the structure of the rare Madagascar 

 mammal, Galidictis striata : F. E. Beddard. 



Institution of Mining and Metallurgy, November 21; — 

 Prof. W. Gowland, president, in the chair. — The deviation 

 of Rand bore-holes from the vertical : J. Kitchin. 

 Although there are altogether 235 bore-holes sunk in the 

 Witwatersrand area, of which forty-five have reached a 

 depth of 3000 feet or more, the author has contented him- 

 self with a review of twenty-two only, in respect to which 

 results sufficiently full for tabulation are available. As 

 regards these, the general characteristics were such that 

 he has tabulated the following ascertained effects : — (i) the 

 bore-holes almost invariably deviate in a northerly direc- 

 tion ; (2) they almost invariably deviate against the strata ; 

 (3) the deviation tends to be greatest when the dip is 

 least; (4) the deviation is not confined to any particular 

 spot or spots in the bore-holes, but seems in most cases 

 to be more or less general throughout ; and (^) there is 

 no appreciable deviation in the case of the flat-lying surface 

 dolomite and any amygdaloidal diabase underlying it, or 

 in the case apparently of surface igneous rock, but in all 

 other instances the deviation is usually marked, and its 

 rate of increase comparatively uniform. In other words, 

 deviation is not observed except where the rocks passed 

 through are bedded and have a dip. The average hori- 

 zontal displacement of the twenty-two bore-holes specially 



NO. 1988, VOL. 77] 



submitted for analysis was 440 feet at a depth of 2000 feet, 

 the minimum being 160 feet in a bore-hole 2000 feet deep, 

 and the maximum 2370 feet in a bore-hole 4200 feet deep. 

 As an appendix, the author gave particulars of a further 

 twenty bore-holes, data of which were less detailed. — The 

 separation of tin-o.\ide from wolfram : A. Treloar and G. 

 Johnson. A record of experiments made by the authors 

 in Cornwall upon " tinny-wolfram " with the view of 

 saving the tin left in the product of the magnetic separator. 

 The most successful results were obtained by taking the 

 separated product in a dry state and boiling it in dilute 

 sulphuric acid, which in a fairly large-scale experiment 

 gave an extraction of 20 per cent, of tin-oxide. Hitherto, 

 since the introduction of magnetic separation for Cornish 

 ores, large quantities of tin-o.xide have been given away 

 in the parcels of wolfram sold, owing to a lack of means 

 to effect this further separation from the tinny-wolfram. 



P.ARIS. 

 Academy of Sciences, November 23. — M. Henri 

 Becquercl in the chair. — Remarks concerning the nitrous 

 isomerisation of isobutyl alcohol : Louis Henry. The con- 

 version of the hydrochlorides of the fatty amines into 

 alcohols by sodium nitrite results in the simple replace- 

 ment of the (NH.) group by (OH) for methylamine and 

 ethylamine. Higher members of the series undergo a 

 more complicated change, isomeric alcohols being pro- 

 duced. Isobutylamine gives isobutyl alcohol, 



(CH3),.CH.CH,.OH, 

 and trimethylcarbinol, (CH3),.C.(OH), the proportion of 

 the latter (about three-quarters) being determined by con- 

 verting it into tertiary butyl chloride. — The determination 

 of the solar elements and the masses of Mars and Jupiter 

 by meridian observations of Vesta : G. Leveau. The 

 whole of the observations made at Greenwich and Paris 

 between the years 1807 and 1904, and numbering 5440, are 

 utilised, and the results compared with those of Le Verrier 

 and Newcomb. — Observation of the passage of Mercury 

 across the sun's disc made with the Gautier equatorial 

 (40 cm.) at the National Observatory of Athens : D. 

 Egrinitis. The atmospheric conditions at Athens were 

 bad, and accurate measurements, in consequence, were 

 impossible. The brilliant ring round the disc of Mercury 

 observed in the transit of i8gi was not seen on this 

 occasion. — The order of the function D(A) of Fredholm ; 

 T. Lalesco. — Some points in the theory of fundamental 

 functions relating to certain integral equations : Bryon 

 Heywood. — The irregular points of convergent series of 

 analytical functions : P. Montel. — Some properties of 

 integrals passing through a singular point of a differential 

 equation : H. Dulac. — The rotatory magnetic dispersion 

 of crystals in the neighbourhood of absorption bands : Jean 

 Becquerel. — Influence of the reaction of the medium on 

 the size of the colloidal granules : .Andr^ Mayer, G. 

 Schaefter, and E. Terroine. Numerous examples are 

 given showing that the addition of traces of acid to 

 negative colloidal solutions, or of alkalies to positive solu- 

 tions, has the effect of increasing the size of the colloidal 

 granules. — .1 new compound of uranium, the tetra-iodide : 

 Marcel Cuichard. Metallic uranium and iodine are sealed 

 up in a vacuous tube, the iodine being heated to 180° C. 

 and the uranium to 500° C. ; the iodide LII^ is thus 

 formed. It is unstable, and readily acted upon by moisture 

 or oxygen. — The synthesis of ammonia by catalysis start- 

 ing from its elements ; Lc5on Brunei and Paul Woog- — 

 A method for estimating very small quantities of zinc : 

 Gabriel Bertrand and Maurice Javillier. The method 

 is based upon the insolubility of calcium zincate, and allows 

 of the separation of o-i mg. of zinc from three litres of 

 solution, a dilution of i in 30,000,000. — Lupeol : P. 

 van Romburgh. A comparison of the lupeol obtained 

 from bresl: (the juice of Dycra Loivii) with that extracted 

 as cinnamate from the gutta-percha of Palaquium Treubii. 

 — Two isomeric methylsparteincs : Charles Moureu and 

 Amand Valetir. ,\n account of two isomeric bases 

 obtained by the decomposition of o-methylsparteinium 

 hydrate. — Experiments on the synthesis of ;8-campholene 

 lactone and on the lactone of 2 : 4-dimethylcyc/opentanol- 

 2-acetic acid : G. Blanc. — The primitive form of the male 

 fig ; Leclerc du Eablon. — The signification of the redden- 



