426 



NA TURE 



[February 28, 1901 



of animal electricity, and No. Il8 contains Volta's accounts of 

 investigations made by him in the period 1796- 1800. No. 115 

 is devoted to de Saussure's research in hygrometry (1783). The 

 three volumes are edited by Dr. A. J. von Oettingen, and are 

 in German, like the other volumes in the series. 



An interesting synthesis ot fumaric acid is given in the current 

 number of the Berichte by O. Doebner. Under the action of 

 pyridine, condensation between glyoxylic and malonic acids is 

 readily effected. The condensjtion m ly be imagined to take 

 place with the intermediate formiUon of maleic acid, but at- 

 tempts to isolate this were unsuccessful. 



In his account last year of the properties of the remark- 

 able hexafluoride of sulphur, M. Moissan mentioned that other 

 bodies were formed at the same time containing sulphur and 

 fluorine, and in the current number of the Comptes rendus he 

 gives, in conjunction with M. Lebeau, a further contribution to 

 this subject. The compound described is sulphuryl fluoride, 

 SO2F2, and it is obtained by the regulated action of fluorine 

 upon sulphur dioxide. The conditions of the reaction had to 

 be carefully studied, as the reaction of these two gases is so 

 violent that explosions frequently occur. The new gas is 

 necessarily accompanied by others, owing to the operations 

 being carried out in glass vessels, and the separation of these is 

 effected by liquefying the whole at - 80° C. and fractionating 

 in vacuo. Sulphuryl fluoride is a colourless, odourless gas, 

 solidifying in boiling oxygen, melting at - 120° C, and boiling 

 at - 52° C. Although in some respects it resembles its halogen 

 homologues, in its stability and inertness in other reactions it 

 recalls the properties of the hexafluoride. Thus it is without 

 action upon water even in a sealed tube at 150° C. M. Moissan 

 remarks that these experiments show that although fluorine is 

 undoubtedly at the head of the halogen group, it is a little 

 removed from the others, having special and characteristic 

 properties which show affinities rather to oxygen than to 

 chlorine. 



The additions to the Zoological Society's Gardens during the 

 past week include a P^tas Monkey {Cercopithecus patas), a 

 Green Monkey {Cercopithecus callitrichiis), an Anubis Baboon 

 (Cynocephaius anuhis), an African Civet Cit ( Viverra civeita), a 

 Denham's Bustard {Eupodotis denhanti), a Royal Fython {Python 

 regius) from Falaba, Sierra Leone, presented by Mr. C. E. 

 Birch; two White-collared M.?ing3Lh&ys, {Cercocebus collaris), a 

 Bay Duiker ( Cephalophus dorsalis) from West Africa, presented 

 by Mr. E. R. Cookson ; a Herring Gull (Lams argentatus), 

 European, presented by Mr. C. A. Hamond ; a Jay {Garrulus 

 glandarius), a Jackdaw {Corvus monedu/a), European, presented 

 by Miss N. Eskell ; a Merlin {Falco oesalon), European, pre- 

 sented by Mr. Gregory Haines ; a Goshawk {Asiur pahim- 

 barius), European, presented by Major-General A. A. Kinloch, 

 C. B. ; a Barn Owl {Slrix Jla/nmea), European, presented by 

 Mr. A. Masters; two D*arf Chameleons {Chamoeleon pumilus) 

 from South Africa, an Axis Deer (Cervus axis) from India, de- 

 posited ; a Hoffmann's Sloth {Cholopiis hoffnianni) from 

 Panama, a Great Ant-eater {Myrtnecophaga jubata) from South 

 America, two Horned Tragopans {Ceriornis satyra) from the 

 South-east Himalayas, four Californian Quails (Callipepla cali- 

 fornica) from California, four Virginian Colins {Ortyx vir- 

 ginianus) from North America, purchased. 



OUR ASTRONOMICAL COLUMN. 



Astronomical Occurrences in March. 

 March 2. loh. 46m. to I2h. 3m. Moon occults k Cancri, 

 (mag. 5-0). 

 6. Outer minor axis of Saturn's ring = I5""24. 



NO. .635. VOL. 63] 



March 7. I3h. 3m. Minimum of Algol (3 Persei). 



9. Mars in conjunction with a Leonis (Regulus), Mars 



3° 49' North. 

 ID. 9h. 52m. Minimum of Algol (/3 Persei). 

 II. Saturn in conjunction with tt Sagittarii (mag. 30). 

 Saturn 1° South. 



13. 6h. 41m. Minimum of Algol (;3 Persei). 



14. iih. Jupiter in conjunction with the moon. Jupiter 



3° 25' South. 



14. 21. Saturn in conjunction with the. moon. Saturn 



3° 26' South. 



15. Venus. Illuminated portion of disc = o •980. 

 15. Mars. Illuminated portion of disc = 0*979. 



24. 7h. 37m. to 8h. 40m. Moon occults a>^ Tauri 



(mag. 5-8). 



25. 6h. 32m. to 7h. 42m. Moon occults / Taur 



(mag. 5-5). 



26. 9h. 15m. to loh. 6m. Moon occults 68 Orionis. 



(mag. 5-6). 

 28. 6h. 1 6m. to 6h. 40m. Moon occults i Cancri 



(mag. 5-9). 

 29> 5b. 30m. to 6h. 33m. Moon occults A^ Cancri 



(mag. s-8). 



Variability of Eros. — The recent announcement by Dr. 

 Oppolzer concerning the variation in the brightness of the 

 minor planet Eros is confirmed by the accounts of two French 

 observers, who communicate their results in the current issue of 

 Comptes rendus (vol. cxxxii. pp. 396-398). 



The first paper, by M. F. Rossard, describes a series of 

 determinations made at the observatory of Toulouse with a 

 Brunner equatorial of o 23 metre aperture. Estimates with 

 comparison stars were taken on the nights of February 14, 

 15, 16 at short intervals. Evidence ot rapid variation was 

 detected, the difference exceeding a magnitude, the extreme 

 range being from 9*3 to ii'o. The times of the various phases 

 observed were as follows : — 



1901 Feb. 14 9 43 min. 



14 ID 48 max. 



15 8 10 max. 

 15 9 32 min. 

 15 10 44 max. 



1 90 1 Feb. 16 7 34 max. 

 16 8 56 min. 

 16 10 3 max. 

 16 II 30 min* 



The comparison of these minima and maxima indicates that the 

 variation in brightness shows a little less than ten periods in a 

 day, i.e. the duration of the period is about 2h. 22m. ; also that 

 the period of increase from minimum to maximum is about 

 15 minutes shorter than the interval from maximum to the 

 following minimum. 



The second note is by M. Ch. Andre. He says the total 

 variation takes place in about 6 hours, and in character is 

 similar to the variable star U Pegasi, but with the stationary 

 period a little longer, so that the planet Eros is to be regarded 

 as a photometric variable, and may consist of a double system 

 formed of two asteroids, whose diameters are slightly less than 

 3 : 2, and whose orbital plane passes through the earth. As the 

 distance of Eros from the earth is about two-thirds that of the 

 sun, the inclination of the line of sight on the plane of the orbit 

 will change rapidly and continuously. The study of these 

 variations will be important in giving a series of light curves, in 

 wh^ch the only variation is that of the inclination of the line of 

 sight on the plane of the orbit of the satellite. 



New Variable Star, i. 1901 (Cygni). — Mr. Stanley 

 Williams announces the variability of the star situated in the 

 position 



h. 



RA. = 19 28 i-Sl/i8cc\ 

 Decl. = + 28° o's /v'^55;. 



The estimated photographic magnitude varied as follows : 



A chart of the region surrounding the star is given, and re- 

 ference made to a previously published photograph of the region 

 by Dr. Max V^oM [Knowledge, 1892, p. 130), on which the star 

 is not shown. (Astronomische Nachrichten, Bd. 154, No. 3687). 



