208 



NA TURE 



[June 29, 1891 



cent fragments. Platinum fuses in a few minutes, and very 

 soon after commences to volatilise, and condenses in the U-tube 

 in brilliant little spheres and fine dust. Aluminium distils very 

 readily, and condenses in the form of a grey powder, containing 

 admixed spherules exhibiting brilliant metallic lu5tre. Tin like- 

 wise distils with facility, and the condensed product usually 

 contains a considerable proportion of a curious fibrous variety 

 of the metal. The distillation of gold in the electric furnace is 

 particularly interesting. Abundant fumes of a light yellowish 

 green colour are emitted at the electrode apertures, and the 

 metal is deposited in the condenser in the form of a powder, 

 exhibiting a beautiful purple sheen. The powder consists of 

 minute regular spheres which, when examined under the micro- 

 scope, appear to reflect the umal yellow colour of gold. Upon 

 the under side of the cover of the furnace three distinct annular 

 deposits are observed, the inner one consisting of yellow globules 

 of considerable size, round which is a metallic deposit of smaller 

 spheres of such a size as to reflect a bright red tint, and outside 

 this is an annular sublimate of a deep purple colour. Man- 

 ganese is remarkably volatile ; a quantity of the metal weighing 

 four hundred grams entirely volatilised in ten minutes. Iron is 

 likewise readily distilled, and is deposited in the form of a grey 

 powder, among which are interspersed numerous small particles 

 exhibiting brilliant surface?. 



Not only are the metaU capable of distillation at the tern, 

 peralure of the electric arc. Silicon rapidly volatilises and 

 condenses in the copper condensing tube in minute spheres and 

 dust. Carbon becomes almost immediately converted to graphite, 

 which distils over into the condenser and deposits in the form 

 of light semi-transparent plates, which by transmitted light 

 exhibit a beautiful chestnut colour. Distilled carbon would thus 

 appear to consist of the fourth variety of the element recently 

 described by M. Berthelot. The refractory alkaline earths 

 appear also to be capable of diitillation in the electric furnace. 

 The experiment succeeds best, however, with a more powerful 

 arc. Employing an arc furnished by a current of a thousand 

 amperes, M. Moissan has distilled one hundred grams of lime 

 in five minutes, the vapour condensing in the copper tube like 

 fine flour. Magnesia passes over somewhat more slowly than 

 lime, but its distillation is one of the prettiest of these remarkable 

 experiments, the tints assumed by the escaping fumes and the 

 brilliance of the incandescent vapour being particularly striking. 



Notes from the Marine Biological Station, Plymouth. —The 



following list completes the summary begun last week of the 



records given during the last six months of the breeding seasons 



of marine animals at Plymouth. Am^ng MoUusca, the Proso- 



branchs Littorini lUtoralis, N.issa reliciUata, Bttccinum (un- 



datum). Purpura {lapillas), Murex erinaceus and Capulus 



hungaricus, the Opisthobranchs Lamellaria perspicua, Aplysia 



punctata, Philini aperla, many Niidibranch?, and the Cephalo- 



pod LoHgo media; am^ng Crunacea, the Claloceri Podon and 



Evadne, various Cirripedia, thj Leptostracan Nehalia bipes, 



several Amphipoda, the Schizopodi Siriella jaltensis, Lepto- 



fiiysis mediterran-a, Macromysis flexuosa and imrmi:, Schisto- 



mysis armosa, the Cumicean Pseudocumz cercaria, the Micrura 



Crangon {vulgaris), fasciaim and sculplus, Palainoii [serratus), 



Palamonetes variant, Pandilus annuUcornis and breviroslris, 



Ilippolyle Cranchii, Virbius varians, Pagurus /avis and Bern- j 



hardus, Galathea sqiiamifera, the Brachyura Porcellana longi- 



cornis ani platycheles, Carcinns [maitas), Pjrtunus depuritor, 



holsalus, arcHXtus, marmarem and pusil/us. Cancer {pa ^urus), 



Pilumnus hirtellus, Xantho fioridus and rivulosus, Eurynome 



(aspera), Stenorhyiichus phalangiuit and tenuirostris ; among 



Echinodermita, Echinus miliaris, Asterina gibbosa, and 



Amphiura elegans ; among Tunicata, Botryllus violaceus and 



Styclopsis grossularia ; and among Cephalochordata, Amphioxus 



NO. 12.35, VOL. 48] 



lanceolalus, have been recorded. It should also be mentioned 

 that the following larvoe have been townetted in large numbers 

 at certain periods : — Veligers, Cyphonantes, Nauplii and 

 Zocea:, and the various larv£e of Echinoderms. 



The additions to the Zoological Society's Gardens during the 

 past week include two Mozambique Monkeys (Cercopitheeus 

 pygerythrus, i i ) from East Africa, presented respectively by 

 Mr. J. B. Tomkins and Mr. B. J. Travers ; two Llamas 

 {Lama peruana, i 9 ) from Peru, presented by Lady Meux, 

 F.Z.S. ; a Rose-crested Cockatoo {Cacatua moluccensis) itova 

 Moluccas, presented by Mrs. Bason ; a Greater Sulphur- 

 crested Cockatoo {Cacatua galerita) from Australia, presented 

 by Mr. Lewis Baily ; a Cinereous Waxbill (Eslrelda cctrules- 

 cens), two Hooded Finches {Spermestes cucullata), a Grenadier 

 Weaver Bird {Euplec/es oryx) from West Africa, an Amaduvade 

 Finch {Eslrelda amandava), two Nutmeg Finches {Munia 

 punctularia), a Black-headed Finch {Munia tnalacca) from 

 India, presented by Mr. W. L. Jeffrey ; two Greater Spotted 

 Woodpeckers {Dendrocapus major) British, presented by Miss 

 Miriam A. Birch Reynardson ; two Alexandrine Parrakeets 

 {Palceornis aletandri) from India, presented by Mr. Wyndham 

 Gibbs ; two Brazilian Tortoises ( Testudo tabulata) from Trini- 

 dad, W.I., presented by Mr. J. S. Toppin ; an Ocellated 

 Skink (Seps ocellatus) from Malta, presented by Col. C. H. 

 Rooke ; two Infernal Snakes {Boodon infernalis jv.) from 

 South Africa, presented by the Rev. G. H. R. Fisk, C.M.Z.S. ; 

 two Emus {Dromaus novcc-hollandia:) from Australia, de- 

 posited ; two Collared Fruit Bats {Cynonycteris collaris) , a 

 Burrhel Wild Sheep {Ovis burrhel), born in the Gardens. 



OUR ASTRONOMICAL COLUMN. 



Comet Finlay (i885 VII.). — The ephemeris for this comet 

 for this week is as follows : — • 



I2h. Paris. M.T. 



R.A. (app.) 

 1893. h. m. s. 



June 29 ... 2 52 20 

 30 ... 2 57 S 

 July I ... 31 49 

 6 33 

 II 16 

 16 o 

 20 42 

 3 25 24 



Stars having Pecltliar Spectra. — On an examination of 

 the stellar spectra photographs taken at Cambridge (U.S.A.) 

 and Arequipa it has been found {Astronomy and Astrophysics 

 for June) that several of them have spectra which qualify their 

 designation as " interesting objects " 



The following list we take from the note referred to : — 



Designation 



R.A. 



Decl. 



Mag. 



Description. 



B.D. -F49°'4i 

 B.D: -I3'893 

 A.G.C 5429 

 A.G.C. 11890 



A.G.C. 22838 

 Z.C. XVIII. 1156 

 A.G.C. 26129 

 B.D. -2i°-6376 



h. m. 



. O I2'2 



■ 4 24'S 

 . 4 43-8 

 , 8 42-4 

 , IS 27-0 



... Type IV. 

 ... F line bright. 

 ... Type IV. 

 ... Type IV. 



... Type III.(H lines bright). 

 Type V. (bright lines). 

 Type III. (H lines bright). 

 8i ... Type IV. 

 9-0 ... Type IV. 



+ 49 44 — 5'4 



-13 17 ... 5-8 , 



-36 23 ... ^\ 



-39 21 ... 71 - 



-71 32 ... — ... 



1647-9 ... -44 5° ••• 8-2 ... 



18 33 ... -6338 ... 9i 

 18597 ... -3817 

 23 6'3 ... -21 32 



All these stars, it will be noticed, with the exception of the 

 first two, have a large southerly declination. „„,„ v c. 



Photographic charts of the region about Z.C. XVIII." 50 

 have confirmed the variability of this star. Among other results, 

 photographs of U Virginis, V Bo5tis, S Geminorum, T Cas- 

 siopeia;, R Piscis Australis et Geminorum, show that these 

 stars give bright hydrogen lines. 



The Sun's Motion through Space.— The methods that 

 have generally been adopted for determining the direction of 

 the sun's motion have been based on the same general principle 



