540 



NATURE 



\Oct. 12, 1876 



and bring it into the regular planetary system. There will not be 

 a transit in September and October for several years. -Note on 

 the transits of hypothetical intra^Mercunal bodies over the sun, by 

 M. Tanssen [See separate article].— Industrial application of solar 

 heat by M. Mouchot. He presented a small solar alembic, with 

 mirror q8 cm. diameter. The boiler contains one litre of wine 

 which boils after half an hour in the sun. The vapour passes in 

 a tube through the bottom of the mirror to the worm where it is 

 condensed. With water in the boiler, and a receptacle for 

 odoriferous leaves or flowers interposed between it and the 

 worm, various essences may be distilled ; or the steam may 

 be used to cook vegetables. -Note on Phylloxera, by M. 

 Lichtenstein.— On the theory of solar spots and the constitution 

 of the sun, by M. Gazan. The spots he explains by continuous 

 cooling of the sun, which changes the inferior layers of vapour of 

 its atmosphere into liquid layers. The sun is a large earth, with 

 nucleus in fusion, vapour and gases in a solid envelope, sur- 

 mounted by a luminous liquid layer, and supporting an atmo- 

 sphere of vapour and gas.-Discovery of the planet 168 ; tele- 

 gram on September 28, by Mr. Joseph Henry, of Washington, 

 to M. Leverrier. Discovered by Mr. Watson at Ann- Arbor.— 

 Discovery of the planet 169 by M. Prosper Henry, by M. 

 Leverrier.— Elements and ephemerides of the planet 164 ^'a. 

 bv M Bossert.— Influence of temperature on magnetisation, by 

 M Gaugain. If a steel bar, with one end in contact with a 

 magnet, be several times heated and cooled between temperatures 

 rand t, the corresponding magnetisms .^/ and w assume variable 

 values. The ratio ^ ~ - expresses the value of thU temporary 



variation. This coefficient increases considerably the further 



. M — Mo 

 you go from the point of contact The ratio —jj^ expresses 



the value of the permanent variation ; Mo being the magnetisa- 

 tion at ordinary temperature at a given point, before heating, 

 and M that obtained after a series of heatings. This coefticient 

 also increases with distance from the point of contact, and more 

 rapidly. The coefficient of temporary variation is independent 

 (within certain limits) of the intensity of the magnetising force, 

 that of permanent variation increases as the force diminishes.— 

 Chemical reactions of gallium, by M. Lecoq de Boisbaudran.— 

 On a skeleton of Hemiphractus, by M. Brocchi.-On the nature 

 of the phenomena of cell division, by M. Fol Phese are studied 

 in Heteropoda, S ea Urchins, and Sagitta. They are occasioned 

 by a fusion between the protoplasm and the nucleus, beginning 

 at the two opposite poles of the nucleus. When reproduction 

 commences the nucleus ceases to be the centre of the system, 

 and the points of fusion become places of convergence for the 

 currents of sarcode which run on all sides towards these new 

 masses The new nuclei result from partial liquefaction of these 

 masses. They are then composed of a mixture of the sub- 

 stance of the old nucleus and the protoplasm of the cell.— 

 Siphonation and migration of gases, by M. Bellamy. He de- 

 scribes several phenomena that may be distinguished from osmose 

 proper (through a septum), in which there are conductors of 

 large surface and length almost nil, while here the conductor has 

 a narrow surface and a relatively great length. 



Geneva 

 Society of Physics and Natural History, August 3.— 

 Prof T L. Soret gave an account of the results of a new series 

 of researches in which he is engaged along with M. Edward 

 Sarasin, on the rotatory polarisation of quartz, principally tor 

 the ultra-violet rays, to which these measurements have not tieen 

 before extended. By means of Broch's method and by employ- 

 ing for this purpose the spectroscope with fluorescent eye-piece 

 devised by M. Soret, a prism of spar and quartz lenses, they 

 have carried their measurements as far as the line ^t-. iney 

 have repeated, besides, a great number of determinations for the 

 different lines of Fraunhofer in the visible part of the spectrum. 

 Their results agree in a satisfactory manner for that part with 

 those of the physicists who have preceded them. Moreover, 

 they have found a striking agreement between their results as a 

 whole from A to R and those which result from the formula 

 given by M. Boltzmann for connecting the rotatory power with 

 the wave-length. 



Vienna 



Imperial Academy of Sciences, July 20.— The following, 

 among other papers, were read -.— Annual period of the insect 

 fauna of Austria and Hungary; II., the beetles (foleoptera), 

 by M. Fritsch. This is in two parts, the first treating of times 



of appearance (observation of 5,025 species at sixty-five stations 

 from 1852 to 1874) ; the second, of annual distribution.— On 

 the vessel-nerves of the Ischiodon, by M. Strieker.— A con- 

 tribution on the action of the heart, by M. Rokitansky. This 

 refers to the action of richly- oxygenated so-called apnceic blood 

 in the arteries and veins on the heart.— Microscopic studies on 

 growth and change of hair, by M. Ebner. He shows that the 

 inner root sheath is essential for hair formation, and though broken 

 through by the hair, it grows during the whole hair- vegetation, in 

 the lower part of the follicle with even greater rapidity than the 

 hair. He defends Langer's view that the new hairs are formed 

 in the old follicle and on the old papilla, and describes fully the 

 mechanism of the process.— Researches on the influence of light 

 and radiant heat on the transpiration of plants, by M. Wiesner. 

 Both luminous rays and dark heat rays strengthen transpiration. 

 Ultraviolet rays have probably little action of this kind. With 

 a gas flame, the influence of the dark heat on transpiration is 

 relatively more prominent than with sunlight (in the one case, 

 eg "57 per cent, of the action was due to the dark heat rays ; 

 iif the other, 21 per cent.). The increase of transpiration of 

 green plants through light is due to absorption of the light by 

 the chlorophyll, and transformation of it into heat, whereby the 

 tension of water vapour in the gas-spaces of the plant is m- 

 creased, and so the relative moisture, and there is an escape of 

 aqueous vapour into the atmosphere. Other colouring sub- 

 stances, such as etiolin, favour transpiration like chlorophyll 

 by their power of changing light into heat, but in less degree.— 

 Contributions to anatomy and morphology of the bud coverings 

 of dicotyledonous woody plants, by M. Wiesner.— On the conse- 

 quences of action of temperature on germination and germinating 

 power of the seeds oi Finns picea, Du Roi, by M. Velten Ihe 

 percentage and rapidity of germination warrants no sure inference 

 as to germinating power of seeds. Heating of seeds may have a 

 favourable or an unfavourable influence on the germmatmg 

 power, according to the physiological state in which the seed is. 

 The duration of the heating has an important influence on deve- 

 lopment of seeds, inasmuch as long! heating at low temperatures 

 can produce the same eff-ect as short heating at high temperatures. 

 —On the theory of waterspouts, by M. Boue. He opposes I< aye s 

 view that these are always formed from below downwards. He 

 has witnessed some formed the other way.— M. Viktor v. Lang 

 described an improvement on M. Broch's method of determinmg 

 the rotation of the plane of polarisation by quartz.— On baro- 

 metric measurement of heights, by M. Hann. This refers chiefly 

 to influence of moisture on the results of such measurement, and 

 shows how to take exact account of it where measurements ot 

 moisture are wanting, at the two stations whose diff^erence ot 

 level is to be ascertained. He calculates from the observed air- 

 temperature and an estimated relative moisture.— On the velocity 

 of propagation of sound-waves from explosions, by MM. Mach 

 and Sommer. The experiments show that this velocity rapidly 

 increases with the violence and suddenness of the explosion. 



CONTENTS 



Pagb 





Our Natural History Collections 



Central Africa 



Our Book Shelf :— 



Beechy's "Electro-Telegraphy ^ ♦ 



Letters to the Editor ^— „ , ,^ , , r „„„ z.oc 



Action of Light on Ebonlte.-Prof. Herbert McLeod ••••525 

 Visual Phenomena.-H.B. Bidbn; Hubert Airy ..... 525 

 An Intra-Mercurial Planet.— G. M. Whipple. . . . • • 3^° 

 Inequality of the Semi-Diurnal Oscillations of Barometric Pres- 

 sure.— Henry F. Blanford, F.R.S 52" 



Miniature Phvsical Geo'OKV. — VV J. SOLLAS .....••• 5^" 



The KwatSd M..,o iCleteoritis.-Prof. Daniel Kirkwoob . 526 

 Comatula rosacea— Major Fred H. Lang . . ... - - "7 

 Influence of Islands on Colour of Animals.— D. Pidgeon 



Are We Drying Up? t" r.I w 



Principles of Time-Measuring Apparatus. 1. cy « 



Gardner. {With IlhistraHons) . . . . . • •' /a/.,,' r/,' 

 Florida Shell Mounds. By Prof. Jeffries Wyman (JFjM ///««■ 



tration) 



Our Astronomical Column : — 



The Variable Star 34 Cygni, Nova 1600 



The Intra-Mercurial Planet Question 



Note on the Sun-spot of April 4, 1876 



Cautions AS TO Intra-MbrcurialObsbrvations ... . . 

 Russian Exploration IN Asia During thb Past Summer ... 534 



Notes -38 



Scientific Serials ■ ' 



Societies and Academies 



Dent 



527 

 £27 

 527 



533 

 533 

 533 

 534 



ERRATUM.-V0I. xiv. p. S06. col. X, line 17 from top, for aMUtd, « c<»^f* 

 read applied to a coastt I 



