14 



NATURE 



[November 30, 1899 



resume's of the present state of our knowledge in various 

 branches of botany : — On the dispersion of seeds, by Prof. 

 Boulger ; and on the importance of light and heat to plants ; 

 on movements of plant organs ; and on fertilisation by insect 

 agency, by the Rev. G. Henslow, read at the meetings of the 

 Society. In the last of these papers, Mr. Henslow sums up 

 strongly against Darwin's dictum that " Nature abhors perpetual 

 self- fertilisation," which, however, he quotes as " Nature abhors 

 self-fertilisation," an assertion never made by Darwin. 



The second volume of Dr. Isaac Roberts' " Photographs of 

 Stars, Star Clusters and Nebulae " is about to be issued from 

 the publishing office of Knowledge. It will contain seventy- 

 two photographs reproduced by the collotype process, in 

 addition to many pages of text. Only a limited number of copies 

 of the work will be available for the public. 



A SECOND fully revised edition of "The Physiology of 

 Plants : a Treatise upon the Metabolism and Sources of Energy 

 in Plants," by Dr. W. Pfeffer, professor of botany in the Uni- 

 versity of Leipzig, translated and edited by Dr. Alfred J. Eward, 

 will be issued immediately from the Clarendon Press. 



The members of the St. Marylebone Natural Science Society 

 apparently derive a large amount of pleasure and instruction 

 from one another, for the report on the meetings held during 

 the present year shows that a number of interesting papers on 

 diverse subjects were read before the Society. Every organisa- 

 tion which creates and fosters a love of natural knowledge 

 furthers the interests of science ; therefore, we are glad to know 

 of the activity of the scientific society of St. Marylebone. 



The only ionising inorganic solvents hitherto found in ad- 

 dition to water are nitric acid and liquefied ammonia. In the 

 current number of the Berichte Prof. Walden, of Riga, gives a 

 preliminary account of experiments with liquid sulphur dioxide, 

 which shows that this liquid acts to an unsuspected degree as a 

 solvent for inorganic and organic substances. Since it permits 

 of double decompositions, and gives electrolysable solutions, 

 liquid sulphur dioxide must now be reckoned as an ionising sol- 

 vent. Many substances dissolve in liquid sulphur dioxide with 

 characteristic colours. Thus the iodides of the alkalis and 

 alkylammoniums dissolve with a yellow colour. As an example 

 of double decomposition, the action of potassium iodide on tri- 

 methylammonium chloride may be cited. These substances in 

 sulphur dioxide solution give a precipitate of potassium chloride. 

 Ferric chloride and ammonium sulphocyanide give the usual red 

 colour of ferric sulphocyanide. The electrical conductivity of 

 salts in sulphur dioxide solutionis not the same in order as that in 

 aqueous solution, nor does the molecular elevation of the boiling 

 point in liquid sulphur dioxide correspond altogether with that 

 found in aqueous solutions. Prof. Walden promises a thorough 

 investigation of the many points of interest raised by this new 

 discovery. 



The additions to the Zoological Society's Gardens during the 

 past week include a Vervet Monkey {Cercopithecus lalandii, <J ) 

 from South Africa, presented by Mrs. A. Rousbey ; a Persian 

 Gazelle {Gazella subgutttiroia, i), a Chaplain Crow [Corvus 

 capellanus) from Persia, presented by Mr. B. T. Ffinch ; two 

 Chipping Squirrels ( Tamias striaius) from North America, pre- 

 sented by Mr. C. M. Stewart ; two Snake Fishes (Polypterus 

 senegalus) from the River Gambia, presented by Mr. J. S. 

 Budgett ; an Indian Antelope (Autilope cervicapra, ^ ), a Banded 

 Parrakeet {Paloeornis fasciatus) from India, a Sooty Phalanger 

 {Trichostirtis fuliginosus,$) from Tasmania, a Fennec Fox 

 {Cants cerdo) from North Africa, deposited ; two Red-backed 

 Buntings {Emberiza riitila) from Japan, purchased. 



NO. 1570, VOL. 61] 



OUR ASTRONOMICAL COLUMN. 



Holmes' Comet (1899 d)- 



Ephemeris for \2h. Greenwich Mean Time. 



R.A. 



h. m. 



Decl. 



Comet Giacobini (1899 e). 



Ephemeris for 12/1. Berlin Mean Time. 



R.A. 



Decl. 



+ 12 137 



12 30-5 



12 47-4 



13 4'4 



13 2C 4 

 13 38-5 



13 557 

 + 14 i3'o 



Spectroscopic Binaries.— (i) a ^«r2;^« {Capella). Prof. 

 W. W. Campbell, from examination of six spectrum plates of 

 the star obtained with the Mill's spectrograph during 1896-97, 

 finds decisive evidence of its being a spectroscopic binary. The 

 component having a spectrum of the solar type showed velocities 

 of 34, 54, 49 and 3 kilometres per second from 1896, August 31, 

 to 1897, February 4. The spectrum of the second component 

 appears to consist chiefly of H7 and the more prominent iron 

 XxwQ?, (Astro. Physical fournal, vol. x., p. 177). (2) a Ursae 

 Mtnoris {Polaris). Photographs of the spectrum obtained in 

 1896 showed no decided evidence of variable velocity. Others 

 taken in August 1899 gave such difTerent values, ranging from 

 -15-2 to -9'o kilometres per second, that the star was sus- 

 pected to be a short period variable, and a curve was plotted 

 from additional observations specially made. {Astro. Physical 

 Journal, x., p. 180). The 1896 values of the velocity lie 

 altogether out of the recent measures, and this is the reason 

 assigned for suspecting the presence of a disturbing force in the 

 form of a third component. The period of the chief pair is 

 about 3d. 23h. All the observations were made with the Mill's 

 spectrograph on the 36-inch refractor. 



In the same number of the Journal, p. 184, Prof. E. B. 

 Frost, of the Yerkes Observatory, gives the velocities in the 

 line of sight of this star, obtained from spectrograms taken with 

 the 40-inch refractor. The resulting values quite confirm the 

 short period variation found by Prof. Campbell, and the range 

 in velocity (7 kilometres) is also closely in agreement. 



Position of Perth Observatory. — Mr. W. E. Cooke, 

 Government Astronomer at the Perth Observatory, Western 

 Australia, has recently, with the co-operation of Sir Charles 

 Todd, of the Adelaide Observatory, determined the latitude and 

 longitude of the station. The latitude was determined by ob- 

 servations of meridian zenith distances of circumpolars, and the 

 final adopted value is 



Latitude 31° 57' 09""63 S. 

 The longitude was found by interchanges ot clock signals 

 between Perth and Adelaide, the adopted value being 

 Longitude = 7h. 43m. 2174s. E, 



Variations in the Spectrum of Orion Nebula. — Prof. 

 Scheiner, in the Astronomische Nachrichten, Bd. 150, No. 

 3593, made some lengthy criticisms of Prof. Keeler's observa- 

 tions of the spectrum of the Orion Nebula, obtained with the 

 Lick telescope. Prof. Keeler's reply is given in No. 3601, and 

 the Astro. Physical Journal, vol. x., pp. 164-8, contains both 

 the reply and a translation of Prof. Scheiner's article. The 

 experiment consisted in obtaining two photographs of the 

 nebula, one on an ordinary plate, the other on an isochromatic 

 plate protected by a greenish-yellow screen. The resulting 

 negatives showed considerable differences in the relative in- 

 tensities of several parts of the nebula. Prof. Scheiner pointed 

 out the doubtful comparison of different types of plates, the 



