564 



NA TURE 



[April 1 1, 1895 



second ediiion is "Outlines of Zoology," by Mr. J. A. 

 Thomson, published by Mr. Y. J. Pentland. The book has 

 evidently been oypreciated by students of zoologj- as a manual 

 for use in the lecture-room, museum, and laboratory. -Messrs. 

 W. H. Allen and Co. have published a third and revised edition 

 of "Practical .Microscopy," by Mr. G. E. Davis. 



The lower sulphide of carbon, CS, appears to have been 

 obtained by Dr. Deninger, of the Dresden Laboratory, in con- 

 siderable quantities, .\nhydrous sodium sulphile and excess 

 of chloroform were heated in sealed tubes, fron which the air 

 had previously been removed, to a temperature about i8o°. 

 Upon opening the tubes after cooling a large volume of gas 

 was discharged, which consisted of sulphuretted hydrogen, a 

 small quantity of hydrogen chloride, and a new gas, which was 

 practically UDa6fected by passage through a solution of caus'.ic 

 soda. This gas was combustible, burning with production of 

 sulphur dioxide, and would appear to be carbon monosulphide, 

 produced in accordance with the following equation : 

 3Na,S -f 2CHa, = H,S + 6NaCl + 2CS. 

 The s.ime gas is obtained, less admixed with impurity, by heat- 

 ing in sealed tubes a mixture of silver sulphide and iodoform, 

 and subsequently allowing the product, consisting of carbon 

 monosulphide and sulphuretted hydrogen, to bubble through 

 caustic soda solution, whereby the latter gas is absorbed. 



3Ap.S + 2CHI3 = II.,S T 6AgI + 2CS. 

 Kn analysis was made of the gas thus obtained, and the result 

 agreed with the f nmula CS. The gas explodes violently in 

 the eudiometer, so that analysis is not readily carried out 

 Tolumetrically ; the explosion pipette was destroyel in a second 

 attemp'. The action of sodium upon carbon disulphide was 

 next studied. When the metal is placed in the liquid disul- 

 phide it becomes coaed with a greyish substance, which pre- 

 vents further action. It was four.d, however, that aniline dis- 

 solves this coaiin', leaving the metal clean ; when carbjn di- 

 sulphide is th;n added, a continuon; evolution of gas occurs, but 

 the greater portion of the ga? does not e cape, being energetic, 

 ally absorbed by aniline, iiolcss \\\t sodium is maintained at the 

 surface of the liquid. After purification of the gas by passage 

 tlirough caustic soda, and through triethyl phosphine to remove 

 carbon disulphide, it is found to burn with a blue flame, with | 

 production of sulphur dioxide and water. The latter is owing ' 

 to admixture of free hydrogen, which can readily be isolated 

 by absorption of the carbon monosulphide in aniline in a 

 Hempel burette. Carbon monosulphide is al-o rapidly ab- 

 sorbed by alcohol. Upon allowing the mixture of hydrogen 

 and carb in monosulphide to stream through tubes immersed in 

 a freezing mixture, the latter gas condensed to a clear colour- 

 less liquid, which rapidly evaporated upon removal from the 

 fieezing mixture. It would thus appear that carbon mono- 

 sulphide is a gaseous substance at the ordinary temperature, 

 but which readily condenses to a liquid in an ordinary freezing 

 mixture, is combustible, and is energetically absorbed by alcohol 

 and aniline. 



The additions to the Zoological Society's Gardens during 

 the pajit week include a Feline Douracouli I^Nyctipilht<us 

 loci/traiis) from .South Brazil, a Squirrel Monkey (Chrysolhrix 

 ■.<iurta.) from Guiana, presented by Mr. .'Vugusto Lewy ; a 

 King-necked Parrakeet (Paliiornis lor.jiiutut) from India, 

 presented by Lady Aitchison ; two Hybrid Widgeon (between 

 Marcca ftntloft, 6 , and Af. chilaiisis, 9 ), bred in England, 

 presented by Mr. J. Charlton Parr; seven Common Skinks 

 {Scincui offlcinalis) from the Sihira Desert, presented by 

 Major Sullivan ; a Ilaast'n Apleryx {Afteryx liaasli), an 

 Auckland NIand Duck {fl^tsontt/a aucilanJUa) from New 

 Zealand, nine Hamadryads {Of'hwphafiis flat's) from India, 

 deposited. 



MO. 1328, VOL. 51] 



OUR ASTRONOMICAL COLUMN. 



The Lvrid Meteors. — Mr. Denning draws attention tothe 

 fact that ihisjear the Lyrid shower may he observed practically 

 in the absence of the moon. Though rarely forming a striking 

 shower, the stream is astronomically imp iriant for the rea-;on 

 that it is probably the only one, besiles the Perseid-, which has 

 its radiant displaced on successive nights of observation. The 

 duration of the shower is Irom April 16 to 23, with a maximum 

 on the 20th, and the displicement of the rad ant is com- 

 paratively small. On .-Xpril 20, the radiant is miniated in R A. 

 2/0% Decl. + 33°, that is, about 1° N. of 104 llerciili-, a st.ir 

 ol the 5th magnitude. Like the Perseids nf .-Vugu t. the Lyiids 

 never fail to show themselves, though they are rarely to be 

 comr'ared with the Perseids in point of richness (Oi/<Tz'a/.;/y, 

 April). The orbit of the swarm is probably identical with that 

 of Comet I, 1S61. 



.\ New Form of Zenith Telescope — The determination 

 of the zenith distances of stars near the zenith appears likely to 

 be greatly simplified by an arrangement recently devised by M. 

 Louis Fabry (Bulletin Ailronomiqin, April). The main idea 

 is to materialise the zenith point so that micrometric measure- 

 ments can be made directly in the field of view. A horizontal 

 telescope is fixed in the meridian, and in front of it is a thin 

 sheet of glass inclined at 45" ; beneath this is a basin of mer- 

 cury. When adjustel so that the reflected image of the cross- 

 wires is coincident with the wires themselves, the wires m,ark 

 the zenith point, and stars of sufTicient briijhiness will also be 

 seen in the field of view after transmission through the glass anj 

 subsequent reflection from the mercury and glass. The gteat 

 objection to this simple plan is the reducion 1 f brightness of 

 the star images, and there is also an objection to observmg 

 stars after reflection from mercury. To overcome these difli- 

 culties, a second telescope is directed towards the first, so that 

 the cross-wires can be seen at the centre of the field, an I the 

 sheet of glass is coated with silver to a thickness that will juu 

 allow the strongly illuminated cross-wires of the *irst telesco|)e 

 to be seen in the second. The first telescope thus serves the 

 purpose of maiking the zenith point, and this is utilised in the 

 second telescope f-T the tueisurement of dis'ances. 



Ascompated with the zenith telescopes in common use, the 

 new instrument has the advantage of greater smiplicity and 

 rigidity, and it is unnecessary to make differential measures of 

 stars north and south of the zenith. It should especially b; of 

 use in such an investigation .is that of the variation of latitude. 



The Orion Nebula. — An exhaustive discussion of the 

 photographs of this nebula, and of the stars in its vicin tv, taken . 

 at Harvard and elsewhere, has been recen'lv completed by 

 Prof. W. II. Pickering (.-/MmrA </ //;<r Hanard C. liege Obstr- 

 valory, vol. xxxii. pa t I.) 146 stars have tieen catalogued, in 

 addition to those given by Bond for the same area, an i a com- 

 parison of magnitudes suggests that a few of the stats are 

 cither variable or have increased in brightness. No clear indi- 

 ca'ions of change in the nebula, either of shape, po-ition, or 

 b illiancy, have been detected in the phoographs taken during 

 the last ten years. By the ingenious artanijement of photo- 

 graphing the nebula thiough a thin perforated >heet of brass 

 placed in contact with the sensitive film, Prof, dickering has 

 constructed a chart of ihe nebula showmg isopholal contours, 

 or lin-s of equal photographic inter sity, which will be verv 

 valua'ile in s ibsequent >carch'ng for evidence of C ange. .V 

 photograph of the spec rum of thenebuli taken with the ob- 

 jective prism shows at a g'ance which regions shine with light 

 of any pati^nar wavelength. The image corresponding to 

 Ihe hydrogen line II7 is seen to resemble most closely the 

 ordin.iry photographs, while the ultraviolet line at A 372 is 

 found particularly strong along the south-ea-t border ol the 

 Huyghenian region. Among the photogra hs reproduced, 

 thai showing the v.ast llebulo^ity which nciily >urroun Is the 

 whole con-tellation of Orion is, perhaps, of ttie greatest 

 interest. This was taken with a portrait lens of about 2.1 inches 

 aperture, and shows the nebulous stream, about 15 ilegrecs in 

 diimeter, which has since been photographe I by Prof Hainnrd 

 (Nature, vol. li. p. 253). Prof. Picke ing gives rcas ms for 

 .supposing that the parallax of this remirk.ible nc'nila is not 

 greater than o"oo3, corre ponding to a di tance of i< 00 light- 

 years. A use'ul account of ihc fiindimcit.il princi|ilcs and 

 proce-scs of astronomical photography, including the deter- 

 minition of photo.;raphic stellar magnitudes, is given in the 

 same volume of the Ainiiils. 



