1 64 



NATURE 



[June i8, 1891 



Mendeleeff, not the anhydride of an acid, but a neutral oxide of 

 a similar chemical character to hydrogen peroxide. It may be 

 best separated from the excess of 40 per cent, acid by removing 

 the latter, after dilution with three times its volume of water, by 

 means of freshly prepared barium phosphate. It cannot, how- 

 ever, be preserved in pure water, as it parts with oxygen so 

 readily, becoming reduced thereby to ordinary sulphuric acid. 

 That it is not an anhydride is proved by the fact that it yields no 

 salts of the type KjSOg with alkalies. Neutral solutions con- 

 taining it, in which it appears to be permanent, may be readily 

 prepared by neutralizing the solution in 40 per cent, acid with 

 caustic soda, potash, or magnesia. The properties of SO4 in 

 either acid or neutral solution are somewhat remarkable. When 

 boiled in contact with platinum wire or platinum black it is ener- 

 getically decomposed with evolution of quantities of oxygen. If 

 the neutral solution is employed, it becomes strongly acid. Indigo 

 solution is oxidized and decolorized slowly, but instantly if a 

 little ferrous sulphate is added. SO4, however, in spite of this 

 ready decomposition into oxygen and sulphuric anhydride, is but 

 a weak oxidizing agent, being incapable even of oxidizing oxalic 

 acid or carbon monoxide. But under certain circumstances it 

 acts as a powerful reducing agent. For instance, if an emulsion 

 of peroxide of lead in 40 per cent, sulphuric acid is brought in 

 contact with a quantity of similar acid which has been subjected 

 to electrolysis so as to charge it with SO4, a rapid evolution of 

 oxygen gas occurs, and the peroxide of lead is converted into 

 ordinary sulphate of lead. In a similar manner precipitated 

 peroxide of manganese is rapidly reduced to manganous sulphate 

 with evolution of oxygen, and silver peroxide likewise dissolves 

 up to a clear solution of silver sulphate with violent effervescence 

 due to the escape of oxygen. Prof. Traube regards sulphur 

 peroxide as built up on the type 802(02), resembling hydrogen 

 peroxide, H2O2. He considers that Berthelot's oxide, S2O7, is a 

 molecular compound of SO3 and SO4, for it does not dissolve 

 in water without decomposition, breaking up into sulphuric 

 anhydride and oxygen, which is evolved. On the other hand, 

 it appears, like SO4, to be perfectly stable in a moderately 

 concentrated solution of sulphuric acid. 



The additions to the Zoological Society's Gardens during the 

 past week include a Macaque Monkey {Macacus cynomolgus S ) 

 from India, presented by Mr. James B. Leckie ; a White-fronted 

 Amazon {Chrysotis leucocephala) from Cuba, presente I by Mrs. 

 Lacabra; a Radiated Tortoise {Testudo radiata) from Mada- 

 gascar, an Angulated Tortoise {Chersina angulata), three 

 Stnooth-bellied Snakes {Homolosoma lutrix) from South Africa, 

 presented by the Rev. G. H. R. Fisk, C.M.Z.S. ; a Green 

 Lizard (Lacerla viridis) from France, presented by Mrs. Hill ; 

 three Horned Lizards {Phrynosoma cornutum) from Texas, 

 presented by Mr. James E. Talmage ; five Squirrel-like Phal- 

 angers {Belideus sciitreus 6 6 6 9 9) from Australia, a Grand 

 Eclectus {Eclectusroratus) from Moluccas, deposited ; two Elliot's 

 Pheasants {Phasianus ellioti ? ?) from China, two Rufous 

 Tinamous {Rhynchotis rufescms) from Brazil, purchased ; two 

 Marbled Newts {Mo/ge marmorata), bred in the Gardens. 



OUR ASTRONOMICAL COLUMN. 



Newly-discovered Markings on Sk-vvvm.— Edinburgh- 

 Circular No. 16, issued by Dr. Copeland on June 10, contains 

 the following information : — 



Mr. A. Stanley Williams, of Burgess Hill, Sussex, has dis- 

 covered three delicate but distinct markings in the equatorial 

 region of Saturn, The first and third of these are round bright 

 spots, somewhat brighter than the white equatorial zone in 

 which they occur. The second is a smaller dark marking on 

 the equatorial edge of the shaded belt which forms the southern 

 boundary of the white zone. Mr. Williams has obtained abun- 

 dant proof of the reality of these markings, but points out that 

 it requires patience and practice to see them readily. It is very 



NO. I I 29, VOL. 44] 



desirable to obtain repeated observations of their times of transit 

 across the planet's central meridian. To facilitate these obser- 

 vations, Mr. Williams has prepared the following tabic, using 

 loh. I4'6m. as the provisional time in which the planet rotate-; 

 on its axis : — 



Approximate Greenwich Mean Time at which the Spots may be 

 expected on Saturn's Central Meridian. 



The Rotation Period of Venus.— The Bulletin de I'Ata- 

 ditnie Royale de Belgique, No. 4, contains a paper, by M. Niesten, 

 of Brussels Observatory, apropos the rotation of the planet Venus. 

 The observations and drawings made by M. Stuyvaert and the 

 author from 1881 to 1890 do not appear to confirm the persist- 

 ence of the dark markings during a long period, as found by 

 Schiaparelli and others. It is also shown that De Vico's period 

 of 23h. 2im. 21 '935. is more in accordance with the observa- 

 tions than Schiaparelli's period of 2247 days. Twelve drawings 

 of the planet, and a map showing all the markings, accompany 

 the paper. 



A New Asteroid (wo). — M, Charlois discovered the 3iotb 

 minor planet on May 16. Its magnitude was 13. 



THE ROYAL GEOGRAPHICAL SOCIETY. 

 "T^HE anniversary meeting of the Royal Geographical Society 

 was held in the University of London on Monday after- 

 noon, the President, Sir Mountstuart Grant-Duff, in the chair. 

 The first business was the award of the medals and othei 

 honours for the year. The Founder's Medal was delivered to 

 Sir Dillon Bell, Agent-General for New Zealand, for transmis- 

 sion to Sir James Hector, K.C.M.G., F.R.S., Director of the 

 New Zealand Geological Survey. The Swedish Minister 

 received the Patron's Medal on behalf of Dr. Fridtjof Nansen, 

 who was unable to attend. Other honours were awarded to Mr. 

 William Ogilvie, for his explorations of the Mackenzie and Yukon 

 regions ; Lieutenant B. L. Sclater, for instruments to be used 

 in the exploration of Nyassaiand ; Mr. A. E. Pratt, for his 

 journeys in Szechuen ; Mr. W. J. Steains, for his investiga- 

 tions on the Rio Doce, South America. Mr. H. J. Mackinder 

 then introduced the students of the Training Colleges who had 

 been successful in obtaining the prizes offered by the Society 

 annually on the results of the Christmas examinations in geo- 

 graphy. Mr. Mackinder spoke briefly on the progress of geo- 

 graphical education, and on the results of the four years' awards 

 to the Training Colleges. 



The Secretary then read the annual report of the Society, from^ 

 which it appears that on May i last the total number of Fellows 

 was 3579, being a net increase of 84 on the previous year. The 

 total income up to the end of December 1890 was ;^953i, and 

 expenditure ;^82i8. The estimated value of the Society's in- 

 vestments is;^25,648, and of its total assets ;^46,248. During 

 the past year, 900 books and pamphlets have been added to the 

 library, and 936 sheets of maps to the map collection, besides 

 25 atlases, 700 photographs, 151 lantern-slides, and 51 views. 



The President then proceeded to deliver the annual address- 

 on the progress of geography during the past year, deahng. 



