March g, 1893J 



NA TURE 



45 1 



The new number of the Journal of the Royal Horticultural 

 Society includes, besides papers on many other subjects, reports 

 of conferences on the begonia and on apricots and plums. 

 There is also a long series of extracts from the Proceedings of 

 the society. 



The second part of the excellent " Canadian Guide Book," 

 by Ernest Ingersoll, has been issued (W. Heinemann). It deals 

 with western Canada, and the author has been at great pains not 

 only to collect full and trustworthy information, but to present 

 it in a clear and attractive style. There are maps and many 

 illustrations. 



The results of an investigation concerning the nature and 

 properties of metallic ruthenium, particularly with respect to the 

 fusing point of this highly refractory rare metal, are contributed 

 by M. Joly to the current number of the Comptes Rendus. M. 

 Joly has accumulated no less than three kilograms of pure 

 metallic ruthenium, and has consequently been enabled to carry 

 out experiments upon it on a comparatively large scale. It will 

 doubtless be remembered that ruthenium and osmium are the 

 two most refractory of the metals of the platinum group. 

 Deville and Debray only succeeded with great difficulty in 

 obtaining a few minute globules of melted ruthenium with the 

 aid of the oxyhydrogen blowpipe. The fusion of this metal 

 is rendered very much more difficult owing to the readiness 

 with which, at these high temperatures, it becomes converted 

 into the volatile tetroxide RUO4. It was apparent therefore 

 that in order to attain success the temperature must be suddenly 

 raised to a point considerably higher than the melting point of 

 the metal ; and in order to effisct this a much more powerful 

 source of heat than the oxyhydrogen blowpipe would be re- 

 quired. M. Joly has therefore employed the electric arc, which 

 has recently been shown by M. Moissan to be so admirably 

 adapted for the preparation of refractory metals. At the high 

 temperature of a powerful arc ruthenium is melted in a few 

 seconds, and without sensible loss by volatilisation in the form 

 of tetroxide. Solid ingots of twenty to thirty grams of the metal 

 have been obtained in this manner without difficulty. As the 

 melted metal cools, however, it becomes covered with a coating 

 of the blue sesquioxide Ru^Os and the dioxide RuOg. In 

 order to remove this the in^jot is placed first in aqua regia, 

 which, however, has no action upon either the metal or the 

 oxides, and subsequently in hydrofluoric acid ; finally the ingot 

 is heated in a stream of hydrogen, when it loses the last traces 

 of oxide and the pure metal remains. Pure ruthenium thus 

 obtained in tolerably large quantities after fusion is a greyish- 

 white metal, more nearly resembling iron than platinum in 

 appearance. Its hardness is about the same as that of iridium. 

 It possesses a crystalline structure and is brittle. The density 

 of the metal after fusion M. Joly gives as 12 '063 at 0° compared 

 with water at 4°. Employing the same electric arc and under 

 equal conditions in all respects, the fusion of ruthenium appears 

 to be attended with appreciably greater difficulty than that of 

 rhodium and iridium, whose melting points are somewhat higher 

 than the melting point of platinum. Moreover, under the con- 

 ditions which suffice for the ready fusion of ruthenium, osmium 

 merely sinters, traces of fusion being just apparent. Osmium 

 therefore is the most infusible of the metals of the platinum 

 group. M. Joly is now conducting experiments with the view 

 of determinining the actual temperatures of these interesting 

 high melting points. 



Notes from the Marine Biological Station, Plymouth : — 

 The week's captures include the Lucernarian Depastrum cyathi- 

 lorme and numbers of the Gephyrean Petalostoma minntttm, 

 Kef. Ephyrae of Aurelia have been abundant ; Hydroid 

 medusae scarcer. Polychaete larvaj and Nauplii continue plenti- 

 ful, and Cyphonautes (larva of the Polyzoan Membranipora 

 NO. 12 IQ. VOL. 47] 



pilosa) has considerably increased in numbers. Echinoderm 

 larvae {Attricularia, Pluleus) have made their first appearance 

 in the season's townettings. The Nemertine Nemertes Netsii 

 and a large eyeless mud-dwelling species of the Polychajte 

 genus Polydora {flava, Clap. ?) are now breeding. 



The additions to the Zoological Society's Gardens during the 

 past week include a Black-faced Spider Monkey {Ateles aler) 

 from Eastern Peru, presented by Miss Gertrude Farmer ; a 

 Macaque Monkey {Macacus cynomolgus, S) from Java, pre- 

 sented by Mrs. Frank Phillips ; a Naked-footed Owlet {Athene 

 noctua) European, presented by Mr. Albert Stevens ; a Four- 

 horned Antelope ( Tetraceros quadricornis, <J ) from India, 

 purchased ; six Wild Swine {Stis cristatus), two Badgers {Meks 

 laxus), born in the Gardens. 



OUR ASTRONOMICAL COLUMN. 

 Comet Brooks (November 19, 1892). — The following is a 

 continuation of last week's ephemeris for this comet : — 



\zh. Berlin Mean Time. 



RA. (app.) Decl. (app.) Log r. Log .i Br. 



1893. h. m. s. o / 



Mar. 9 ... o 46 27 ... + 20 46-1 ... 0-1842 ... 0-3563 ..0-47 



10 ... 47 22 ... 34-4 



11 ... 48 17 .. 230 



12 ... 49 II ... 12*1 



13 .. 50 4 ... 20 I'S ... 01946 ... 03731 ... 042 



14 ... 50 57 ... 19 51-5 



15 ... 51 49 ... 19 4I-0 



16 ... o 52 41 .. 19 312 



This comet will soon be lost in the rays of the sun. The unit 

 of brightness took place on November 21 -5, 1892. 



Comet Hol.mes (1892, III.). — M. Schulhof gives the fol- 

 lowing ephemeris of this comet for the ensuing week :— 



R.A. (app.) Decl. (app.) 



1893. h. m. s. o / « 



March 9 ... 2 43 71 ... 35 8 11 



10 ... 44 52-2 ... 10 58 



11 ... 46 37-2 ... 13 46 



12 ... 48 23-4 ... 16 35 



13 •■• 50 94 ••■ 19 24 

 H ••• 51 557 •■• 22 14 



15 ... 53 42-2 ... 25 3 



16 ... 2 55 29-0 ... 27 53 



Universal Time. — On February 6 last the Bill declaring 

 the legal time for Germany to be that of the I5lh meridian 

 east of Greenwich, that is, one hour in advance of Greenwich 

 time, passed the third reading. This law will be brought into 

 force on April i. The Observatory for March informs us that, 

 in a letter addressed to the Astronomer Royal, it is stated by 

 Dr. Schran that a similar Bill has been laid before the Austrian 

 Government, and "it is hoped that the change will be made 

 simultaneously with Germany." The draft of the latter Bill, 

 which we take from the same number, provides :— 



(i) That the legal time in Austria is the mean solar time of 

 the meridian 15° east of Greenwich. The same to replace, on 

 April I, 1893, the present local times for legal, civil, and all 

 other purposes. 



(2) The Government is authorised to make the changes in the 

 school and industrial hours which will become necessary in con- 

 sequence of the adoption of the above. 



The Bielids, 1892. — M. Bredichin, in Astronomisclun 

 Nachrichten, 3154, has a short note on the Bielids, in which he 

 says that the observations made in America on November 23 

 last show that the meeting of the densest part of this swarm 

 with the earth has taken place almost four days earlier than in the 

 year 1885, or, in other words, that the descending node of the 

 stream has receded almost 4° to the west during the period be 

 tween the end of 1885 and the end of 1892. The cause of this 

 recession is, he says, due to Jupiter, the perturbations set up by 

 this planet accounting for the mean daily motion which is neaily 

 equal to that possessed by Biela's comet. 



An approximate computation of the special perturbations for 

 the whole period during which Jupiter had any influence gave 



