no 



NA TURE 



[June 2, 1892 



sisting of a mixture of free arsenic and paracyanogen. When 

 brought in contact with concentrated sulphuric acid and 

 slightly warmed, mutual decomposition occurs, with liberation of 

 sulphur dioxide and carbon monoxide, the nitrogen remaining 

 in the form of ammonium sulphate. Iodine reacts with arsenic 

 cyanide in an energetic manner, even in the cold, forming 

 iodides of arsenic and cyanogen without the volatilization of any 

 iodine. With potassium chlorate, arsenic cyanide forms a mix- 

 ture which detonates with considerable violence when struck. 



The additions to the Zoological Society's Gardens during the 

 past week include two Black-backed Jackals {Cams mesomelas) 

 from South Africa, presented by Master Logan ; two North 



African Jackals ( Canis anihus), four Gerbilles ( Gerbillus 



sp. inc.), an Egyptian Jerboa {Dipus agyptius), six Leith's 

 Tortoises {Testudo leithii), five Common Skinks {Scincus 

 officinalis), an Egyptian Eryx {Eryx jaculus), a Schneider's 

 Skink (Eumeces schneideri), two Crowned Snakes {Zamenis 

 diadema), a Hissing Sand-Snake {Psammophis sibilans) from 

 Egypt, presented by Dr. J. Anderson, F.R.S., F.Z.S. ; a 

 Cinerous Vulture ( Vultur monachus) from Aden, presented by 

 Mr. W, H. Still; a Q.QmxnonV&ii.io'^\{Pavo cristatus cJ)from 

 India, presented by Colonel Bagot-Chester ; two African Love- 

 Birds {Agapornis pullaria) from West Africa, presented by Lady 

 McKenna ; a Chinese Goose {Anser cygnoides <J ) from China, 

 presented by Miss Hill ; two Common Vipers ( Vipera berus), 

 four Common Snakes {Tropidonotus natrix), a Slow worm 

 {Anguis fragilis), British, presented by Mr. C. Browne ; a 

 Mocassin Snake {Tropidonotus fasciatus) from North America, 

 presented by Master Denny Stradling ; two Purple-capped 

 Lories {Lorius domicella) from Moluccas, two Scaly-breasted 

 'Lor^&z\.% {Trichoglossus chlorolepidotus) from Timor, deposited ; 

 four Common Sheldrakes {Tadorna vulpanser, 2 (J , 2 ? ), four 

 Ringed Doves ( Columba palumbarius, 2 (J , 2 $ ), European, 

 purchased ; two Black-eared Marmosets {Hapale penicillata), 

 born in the Gardens. 



OUR ASTRONOMICAL COLUMN. 



Winnecke's Periodic Comet, 1892. — The following 

 ephemeris for this comet has been extracted from Astrono- 

 mische Nachrichien, No. 3083. The comet itself is becoming 

 decidedly brighter, and will be found just between the Great 

 Bear and Leo Minor. 



Berlin Midnight. 



1892. App. R.A. App. Decl. log A. log r. Br. 



h. m. s. o / // 



June 2 10 50 23-4 -1-43 II 46-0 9-9949 9*5376 8-6i 



3 48 52-4 4 31 '4 



4 47 16-4 42 56 597 



5 45 34-6 49 ID -6 



6 43 46-4 41 27 9-9837 9-5012 1072 



7 41 507 32 34-0 



8 39 47-0 23 42-0 



9 37 34 '4 14 23-5 



Saturn's Rings. — At the present time the earth may be 

 said to be very nearly in the plane of Saturn's Rings, thus 

 affording observers an opportunity of examining the ring from 

 the sectional point of view. M. Bigourdan communicates to the 

 Comptes rendus (No, 21) the results of a study he has just 

 made, with reference to some peculiarities he has found to 

 exist. The preceding arm of the ring, he says, presented 

 nothing very abnormal, but it appeared to thin rather than 

 thicken whilst approaching the planet. The amount of thinning 

 in the case of the following arm was much more striking. At 

 a distance of two-thirds of the length of the arm it com- 

 menced to leave the outside edge, continuing gradually, and 

 producing " the appearance of a luminous angle, regular and 

 very pointed, the apex of which joined to the disk of the 

 planet." Observed again on May 21, the following arm 

 showed a protuberance situated near Cassini's division. Ih 



M. Bigourdan's own words, the above appearances could be 

 produced by an " elevation of the level edging the separation 

 of Cassini, and producing on the opposite face a luminous pad 

 which would nearly double the apparent thickness of the ring." 



NO. I 179, VOL. 46] 



GEOGRAPHICAL NOTES. 



Petermann's Mitteilungen for June contains the long-expected 

 account of Emin Pasha's return expedition to the equatorial 

 lakes, written by his companion, Dr. Stuhlmann. Leaving 

 Kahura in March 1891, they traversed an unknown region to 

 the southern shore of Lake Albert Edward, which they followed 

 round its western side, and marched as far north as the 

 Ituri in 2° 13' N. Here the party had to turn. Emin met a 

 number of his old followers living near Kavalli, on Lake Albert, 

 and many of them joined his expedition. The return journey 

 was disastrous. An outbreak of small-pox made it necessary to 

 divide the expedition ; Emin was left behind, while Stuhlmann 

 went on with those able to travel and reached the German 

 station of Bukoba on Lake Victoria in February 1892. The 

 scientific observations made necessitate certain corrections on 

 the map of this part of Africa. Mount Mfumbiro is further 

 west than originally supposed, and may even lie within the 

 boundaries of the Congo State. It is a volcanic chain, one of 

 the peaks of which. Mount Virungo, is apparently still active. 

 Stuhlmann gives the level of Lake Albert Edward as 2750 feet 

 instead of 3307 as determined by Stanley. 



Sir William Macgregor continues to give proofs ot 

 remarkable energy as an explorer, and of tact and skill as 

 Administrator of British New Guinea, In the early part of this 

 year he has been engaged in a series of journeys through the 

 south-eastern districts of the possession, and everywhere he has 

 found the natives peaceful and friendly. In a recent coasting 

 trip he passed several islands, which at first sight appeared 

 uninhabited, but on landing he discovered that this appearance 

 was due to their singular configuration. A narrow belt of 

 gently sloping land led from the sea to a steep wall of coral 

 rock, from 300 to 400 feet high, from the summit of which an 

 undulating plateau was seen dipping inland. Here the villages 

 were built, from 50 to 100 feet below the level of the encircling 

 rim, and sheltered from the trade-winds. Sir William con- 

 siders these islands to be upraised atolls, modified in most 

 cases by subsequent wave action on the shore strips. 



Lieutenant T. II. Barnes, on behalf of the Bolivian 

 Government and the Argentine Geographical Society, is inves- 

 tigating the navigability of the Rio Otuquis, a tributary of the 

 Upper Paraguay, in the hope of opening a new route for Bolivian 

 trade. 



Lieutenant Mizon, compelled by the passive resistance of 

 the Royal Niger Company to relinquish his projected journey 

 by the Benue to Lake Chad, has (according to La Politique 

 Coloniale) crossed the watershed to the Congo Basin, and on 

 his way from the Benue to the Sangha, traversed the hinter- 

 land of the German Cameroon colony, one of the rapidly- 

 shrinking blank spots on the map of Africa. Reports from 

 Tripoli state that Captain Monteil is pushing on from Kano, 

 in Sokoto, to Bornu and Lake Chad, 



The collection of educational appliances, books, atlases, &c., 

 made by Mr. J. Scott Keltie on behalf of the Royal Geo- 

 graphical Society in 1885, has been lent to the Teachers' Guild 

 of Great Britain and Ireland, in whose rooms at 74 Gower 

 Street it has been admirably arranged by Miss Busk. This col- 

 lection, which after its original appearance in London was shown 

 in most of the large towns in the country, has never been more 

 effectively displayed. When first brought together, the inferiority 

 of the British school atlases and text-books to the German and 

 French productions was very marked ; but during the last seven 

 years English publishers have made great advances, and several 

 of the newer and better publications have been added. It 

 would be most desirable if the department of English books, 

 maps, and geographical appliances could be made thoroughly 

 representative, so that teachers would have a real opportunity of 

 comparing the best work of 1892 with that which was current in 

 1885, 



Mr. H. J. Mackinder, Reader in Geography at Oxford, 

 has recently returned from a brief visit to the United States, 

 where he has been devoting special attention to the state of the 



