December 2i, 1905] 



NA TURE 



191 



Anthropological Institute, November 21. — Exhibitions. — 

 Collection of photographs from Arizona: J. S. Chase. 

 These included typical types of the natives, and also illus- 

 trated the Mogui snake dance and other ceremonies. — 

 Collection of objects from Siam, including weapons, pottery, 

 and musical instruments : M. Bidder. — Paper. — Boome- 

 rangs : N. W. Thomas. The author explained the differ- 

 ence between the return and non-return boomerang, and 

 showed the reasons for the peculiarity of the former kind. 

 Diagrams of the different flights were exhibited, as well 

 as a large collection of Australian boomerangs and African 

 throwing knives. 



Cambridge. 

 Philosophical Society, November 13. — Prof. Livsing 

 in the chair. — Polarisation phenomena at Guelma in the 

 eclipse 1905 August 30 : H. F. Nevvail, F.R.S. The visual 

 observations combined with the photographic records 

 proved that the plane of polarisation of the light diffused 

 by the earth's atmosphere during the eclipse was very nearly 

 horizontal. Photographic records, obtained with a Savart 

 polariscopic camera for the purpose of quantitative measure- 

 ments of the relative amounts of polarised and unpolarised 

 light in the corona, showed that the polarised portion of 

 the atmospheric light was equal in intensity to the radially- 

 polarised portion of the coronal light at a distance of about 

 1^ diameters from the sun's limb. Thus the phenomena 

 of a radially polarised corona seen through a plane polarised 

 atmosphere are somewhat complicated. The results 

 obtained by photographing the corona through a large 

 Nicol prism, which was set to transmit successively the 

 vertical component and two components which were in- 

 clined on each side at 45 to the vertical and consequently 

 perpendicular to one another, not only show the strong 

 radial character of the polarisation of the corona, but also 

 seem to suggest that there is a selective action, and that 

 the prominent streamers of the corona are markedly 

 polarised. A photograph taken with a new form of 

 polarising spectrograph shows a very marked difference in 

 the intensities of the tangential and radial components ; 

 but a curious feature in it is that the Fraunhofer lines 

 are not detected in either spectrum, though the conditions 

 are such as must be regarded as very favourable for their 

 detection. — Suggestions for a theory of the Milky Way and 

 the clouds of Magellan : A. R. Hinks. — The effect of the 

 lunar deflection of the vertical on latitude observations : 

 B. Cookson, The attraction of the moon would cause the 

 plumb-line to be deflected through an angle of o"-02 at a 

 maximum, if the earth were a rigid body. It is pointed out 

 that observations made for the -purpose of determining the 

 constant of aberration and variation of latitude by Kiistner's 

 'method are suitably arranged for showing this deflection. 

 A series of observations made at Philadelphia is discussed, 

 but fails to show the direct lunar effect, though it shows 

 an oscillation with a period of half a lunar day, which 

 may be due to the attraction of the ocean tides. 



November 27. — Prof. Marshall Warn, president, in 

 the chair.— Some experiments on Canal-strahlen : Prof. 

 Thomson. Experiments were described showing that 

 when the stream of positive ions which form the Canal- 

 strahlen fall on a solid, slowly moving kathode rays 

 start from the part of the solid struck by the positive 

 ions ; again, metals struck by the Canal-strahlen dis- 

 integrate, and the metal is deposited on the walls of the 

 discharge tube ; ionisation was shown to accompany the 

 passage of the Canal-strahlen. It is suggested that the 

 reason the a particles of radium lose, as shown by Ruther- 

 ford, their power of ionisation when their energy falls to a 

 value which, though less than the initial energy possessed 

 by the a particles, is enormously greater than the positive 

 ions in the Canal-strahlen, may be that the a particles 

 lose their charge when their velocity falls below a certain 

 value by combining with a negative corpuscle ; the value of 

 this velocity is calculated, and it was shown to be between 

 10 8 and io° cm. -sec. The spectra produced by Canal- 

 strahlen were discussed, and it was shown that though 

 these rays give rise to the sodium lines when they fall 

 upon sodium salts, they do not do so when they fall upon 

 the pure metal. — Experiments on the retention of an 

 electric charge by gases : W. A. D. Rudge. — The effect 



no. 1886, vol. ys] 



of hydrogen on the discharge of electricity from hot 

 platinum : O. W. Richardson. An account of experi- 

 ments on the ionisation produced by a platinum tube in 

 air when hydrogen was allowed to diffuse from inside the 

 tube. The negative ionisation was unaffected, whereas the 

 positive was increased by an amount proportional to the 

 quantity of hydrogen diffusing through. The experiments 

 indicate that the increase in the negative leak produced 

 by an atmosphere of hydrogen is due to a change produced 

 by the latter in the surface of the metal, possibly by the 

 formation of an electrical double layer. The experiments 

 on the positive ionisation tend to show that the hydrogen 

 dissolved in the metal is in the form of positive ions. — On 

 colour-inheritance in rats : L. Doncaster. Among the 

 varieties of domestic rats there are, in addition to albinos, 

 two types of colour, black and brown (grey). The colour 

 in either case is distributed in one of three very constant 

 patterns ; rats may be (n) self-coloured, with or without 

 a small white mark on the chest ; (b) coloured above and 

 white below; (c) piebald, with coloured " hood " and back- 

 stripe, elsewhere white. In inheritance, brown is dominant 

 over black, and both over albino. Albinos may bear the 

 black or brown determinant, as in mice, rabbits, &c. 

 When a self-coloured rat is crossed with a piebald, the 

 young have the intermediate pattern (b) ; this is a hetero- 

 zygous form, and when two of this type are bred together 

 they throw selfs, piebalds, and heterozygous young like 

 themselves. Albinos can also bear pattern-determinants, so 

 that an albino bearing " self " bred with a piebald throws 

 heterozygous young of type (b). Self-coloured rats may be 

 entirely coloured or may have a white mark on the chest, 

 but since either form can throw the other, it appears that 

 this is a fluctuating character, and that the pure " self " 

 and white-marked form are not allelomorphic with one 

 another. — A preliminary communication on the life-history 

 of Pleistophora periplanetae (Lutz and Splendore) : W. S. 

 Perrin. — On the osmotic pressure of alcoholic solutions : 

 P. S. Barlow. — Two wheels connected by an axle rolling 

 on a rough horizontal plane : G. M. K. Leggett. — A series 

 of optically active nitrogen compounds containing the ally] 

 group : Miss M. B. Thomas and H. O. Jones. The 

 investigation of the relation between the constitution and 

 rotatory power of substituted ammonium ions is being con- 

 tinued. A series of five compounds containing the phenyl, 

 methyl, and allyl groups, together with the ethyl, propyl, 

 isopropyl, isobutyl, and isoamyl groups respectively, has 

 been examined. 



Paris. 

 Academy of Sciences, December II. — M. Troost in the 

 chair. — On the distillation of gold, the alloys of gold with 

 copper and tin, and on a new method of preparation of 

 the purple of Cassius : Henri Moissan. Gold can be 

 easily distilled in the electric furnace, its boiling point 

 being higher than that of copper, but lower than that of 

 lime. By condensation on a cold tube, the vapour is 

 condensed partly in the form of moss gold, partly as 

 microscopical crystals. The general properties of the con- 

 densed gold agree with those of finely divided gold. In 

 the alloys of gold and copper, or gold and tin, the copper 

 and tin distil before the gold. By distilling an alloy of 

 tin and gold, a purple of Cassius is obtained in the dry 

 way. — Nepheline syenites from the Los Islands (French 

 Guinea) : A. Lacroix. The various types of syenite in 

 these islands are discussed in detail, and complete analyses 

 are given for three typical specimens. — The babits of bees 

 and the colours of flowers : Gaston Bonnier. According 

 to the author, the contradictory experiments of various 

 observers on the relations between bees and colour are due 

 to a lack of knowledge of the habits of bees. There is a 

 division of labour among the honey-fetching bees, the 

 duty of those first issuing from the hive being to seek out 

 honey, and not to fetch it. After a certain hour all the 

 bees are engaged in fetching and carrying, and none in 

 hunting for fresh sources of honey, and hence in selective 

 experiments of this sort quite different results can be 

 obtained according to the hour of the day fixed for the 

 experiment. The author's own experiments lead to the 

 conclusion that the bees are not influenced by colour in 

 their search for honey. — Spectroscopic observations made 

 during the eclipse of the sun of August 30, 1905 : P. 



