June 8, 1882] 



NATURE 



137 



]iery Ventilation, Alan Bagot (Kegan Paul) ; Report U.S. 

 Geographical Surveys, vol. vii. Archxology (Washington) ; Report 

 of the Metropolitan Board of Works, 18S1 ; Botanical Atlas, parts 

 I and 2, D. M 'Alpine (W. and A. K. Johnston) ; Ancient Water 

 Line-, D. Milne Home (Edinburgh, Douglas) ; Laboratory 

 Guide, A. H. Church (Van Voorst) ; Wolf's Naturwissen- 

 sch;ifilich-Mathematisches Vade-Mecum ; Madeira, its Scenery 

 and how to see it, Ellen M. Taylor (Stanford) ; The Founda- 

 tions of Mechanics, W. F. Browne (Griffin and Co.) ; Land 

 Nationalisation, A. R. Wallace (Triibner and Co.). 



The additions to the Zoological Society's Gardens during the 

 past week include a Rhesus Monkey (Macacus erythremia) from 

 India, presented by Capt. E. B. Stephens, R.N. ; a Tig-tailed 

 Monkey (Macacus tiemcsirinus) from Java, presented by Miss 

 R. M. Stanley ; two Striped Hyaenas (P/yu-tia striata) from 

 India, presented by Mr. N. H. Beyts ; a Cape Zorilla (Ictonyx 

 aoriila) from Cape Colony, presented by Capt. Farmer, s.s. 

 Pretoria ; a Three-striped Paradoxure (ParaJoxurus trivirgatus) 

 from India, presented by Mr. R. A. Sterndale ; a Puma (Felis 

 concolor) from America, presented by Capt. J. Jellicoe, R.M. 

 s.s. Moselle; an American Tantalus (Tantalus loculator) from 

 Columbia, presented by Mr. H. B. Whilmarsh, R.M. s.s. Moselle; 

 a Java Sparrow (Padda oryxivord) from Java, presented by Miss 

 M. North; a Landrail (Crex pralensis), British, presented by 

 Mr. A. Battiscombe ; a White Pelican (Pelecanus onocrotalus) 

 from North Africa, presented by Mr. C. G. Bolau ; a Lesser 

 White-nosed Monkey (Cercopithecus pctaurista) from West 

 Africa, an Emu (Dronueus novcehollandice) from Australia, four 

 Summer Ducks (Aix sponsa) from North America, three Brant 

 Geese (Bernicla brenta), two Common Wigeons (Marcca pene- 

 lope), a Common Buzzard (Bitleo vulgaris), European, deposited ; 

 two Great Anteaters (Myrmecophaga jnbata) from South America, 

 a Negro Tauiarin (Midas ursulus) from Guiana, a Purple Heron 

 [Ardea purpurea) from Java, a Bme-crou ned Hanging Parra- 

 keet (Loriculus galgulus) from Malacca, two Rose-breasted 

 Grosbeaks (Hedymeles I udovicianus) from North America, a 

 Bell's Cinixys (Cinixys belliana) from Angola, purchased; a Red 

 Deer (Cervus elaphus), born in the Gardens ; two Herring Gulls 

 (Larus argciitatus), two Impeyan Pheasants (Lophophorus impey- 

 anus), four Horned Tragopans (Ccriornis salyra), two Peacock 

 Pheasants (Polyplectron chinquis), bred in the Gardens. The 

 following species of insects have emerged in the Insect House 

 during the past week — Silk Moths : Actios selene, Altacus 

 mylitta, Attains cynthia, Telea polyphemus ; Butterflies : Lime- 

 nitis silylla, Argynnis paphia, Lycana iolas ; Moths : Chawo- 

 carupa elpcnor. Sphinx pinastri, Scsia spheciformis, Sciapteron 

 tubaniforme, Callinwrpha dominula. 



OUR ASTRONOMICAL COLUMN 

 The Comet (18S2 a). — In a circular issued from Lord Craw- 

 ford's Observatory on May 29, Dr. Copeland remarks that the 

 .spectrum of the nucleus of the present comet deserved the 

 closest attention, as it showed "a sharp bright line coincident 

 with D, as well as strong traces of other bright lines, resembling 

 in appearance those seen in the spectra of 7 Cassiopeiae and 

 allied stars." For some weeks the head had exhibited white 

 light, which might be inherent in the comet or the reflected light 

 "f the sun ; on May 28 the nucleus began to throw out yellow 

 : ays. which on June I were also given out by parts of the tail 

 immediately behind the head. Of 7 Cassiopeiae, Secchi writing 

 in 1877, says : " Le plus remarquable de ces etoiles exceptioneiles 

 est 7 de Cassiopee, qui presente les raies spectrales de l'hydrogene, 

 non pas noires, par renversement, mais directement brillantes, 

 curiosite unique jusqu'ici dans tout le ciel. 11 n'y a que $ de la 

 Lyre qui ait quelquefois les raies brillantes, et encore pas toujours, 

 parce qu'elle est variable " ; and he further writes of £ Lyrae, 

 " Elle nous a montre une fois, an maximum d'eclat, les raies 

 brillantes de l'hydrogene, comme 7 de Cassiopee, chose que 

 nous c'avons plus vue ensuite, bien que nous l'ayons souvent 

 cherchee. " 



The Radcliffe meridian observation of the comet on May 20, 

 communicated by Mr. Stone last week, shows that the place 

 calculated from the orbit we then published required only the 

 following small corrections : — A o . cos S = - i"-S A 8 = + d."'0. 



The Kiel observation on May 31 indicates corrections of + 4" 

 in R.A., and - 19" in declination. 



The positions given last week for June 10 and II are not 

 likely to require material correction. In seeking for the comet 

 in daylight on those dates, care should be taken to focus accu- 

 rately (for this purpose Mercury or Venus may be available), 

 and a pretty long "dew-cap" or a cardboard tube should be 

 fitted to take off the direct sunlight from the object-glass. At 

 so short a distance from the sun, it will of course be necessary to 

 use a dark glass, but it may be we'.l that the illumination of the 

 field should not be diminished much beyond that which the eye 

 will readily bear. More than one astronomer considered he had 

 missed seeing the first comet of 1847 in daylight on March 30, 

 by using too dark a glass ; this was the opinion of Dawes, who 

 could not otherwise explain his want of success. 



On August 9 the comet situated near the star 16 Virginis will 

 have the same theoretical intensity of light as at the first Harvard 

 College observations on March 19, setting in London about ih. 

 50m. after the sun. On July 5, when not far from Regulus, the 

 intensity of light is equal to that on May 6. 



The Transit of Mercury, 1SS1, November S. — This 

 phenomenon was fully observed at Sydney, by Mr. H. C. 

 Russell and seven assistants. The mean results are as follows, 

 in Sydney, M.T. :— 



h. m. s. 



First contact — external 8 21 57*53 a.m. 



,, — internal 8 23 40'6J; a.m. 



Last contact — internal 1 40 25 - l6p.m. 



,, — external 1 42 9'22p.m. 



If we calculate with Leverrier's Tables of the Sun and Mercury, 

 and adopt his diameters, the above observations show differences 

 for the internal contacts of +22'9s. and +26 '2s. respectively. 



The Small Planets. — The number of known members in 

 this group is now 225, the last one having been discovered by 

 Palisa at Vienna on April 19. It appears to belong to the more 

 distant division of the group, the period of revolution exceeding 

 six years. 



The Cordoba Zones. — We have received vol. ii. of " Re- 

 sultados del Observatorio National Argentino en Cordoba," 

 containing the observations of stars in zones, made during the 

 year 1872, and shall give an early account of this important work, 

 for which astronomy is indebted to Dr. Gould's untiring energy 

 and zeal, and the enlightened liberality of the Argentine Govern- 

 ment in promoting the interests of science. 



CHEMICAL NOTES 



In the Chemical Section of the Meeting of Bohemian Natu- 

 ralists in Prague, on May 27, B. Brauner (Fellow of The Owens 

 College) communicated a paper on the atomic weight of didy- 

 mium. The author's former determinations gave the number 

 146-6, but after further purification he finds now didymium to be 

 145 '4. Both samples were entirely free from any known earth 

 metal. Assuming that both numbers are true, the author re- 

 marks that the only explanation which can be given, is that 

 "didymium" is a mixture of two (or more) bodies, one, whose 

 atomic weight is smaller than I45'4, and a second, whose atomic 

 weight is greater than 146 6. Thus it is clear that the chemistry 

 of didymium becomes as complicated as that of "erbium, 

 which was thought to be a simple earth, and later on was split 

 up into the following earths, viz. real (1) erbia, (2) terbia, (3) 

 scandia, (4) ytterbia, (4) thulha, and (6) holmia. '1 he evidence, 

 that the mineral cerite contains other earth metals besides cerium, 

 lanthanum, and didymium, has been given by the author some 

 time ago (Monalshefte iii. 1 ) when he found that the spark-spec- 

 trum of the portions intermediate between lanthanum and 

 didymium, as well as of those between didymium and cerium, 

 contains new lines, not belonging to any known cerite metal. 

 The author is pursuing his researches in the laboratories of the 

 Owens College. 



Zimmerman, who recently determined the densities of gaseous 

 uranium tetrachloride, and bromide, has obtained pure metallic 

 uranium, and made measurements of its specific heat, which 

 completely confirm the number 240 as the atomic weight of this 

 metal (Berichle, 15, 847). 



