y^ine 23, 1S87] 



NATURE 



185 



med. This remarkable body, which has hitherto baffled all 

 cmpts at isolation, is now shown to be a gas, perfectly stable 

 uji to a very high temperature, of a peculiar odour, differing from 

 that of ammonia, exceedingly soluble in water, and of basic pro- 

 perties. In the course of his work upon the diazo-compounds of 

 the fatty series. Dr. Curtius treated diazo acetic ether with hot, 

 strong potash, and obtained the potassium salt of a new diazo- 

 fatty acid, which on addition of mineral acids yielded yellow 

 tabular crystals of the free diazo-acid. On digesting the yellow 

 aqueous solution of this acid with very dilute sulphuric acid the 

 colour disappeared without the usual evolution of nitrogen ; and 

 on cooling a magnificently crystalline substance separated out, 

 which was shown by analysis to be no other than the sulphate of 

 amidogen, (NH.j)^ • H5SO4. These crystals remained unchanged 

 at 250°, but on strongly heating over a flame melted with 

 explosive evolution of gas and deposition of sulphur. On 

 warming this salt with potash solution t!ie free diamide, (NHa")-. 

 was expelled as a gas which changed red litmus into blue, and 

 .rendered itself evident by its irritating odour. The gas fumed 

 in contact with hydrochloric acid forming the hydrochloride, 

 and on leading it into sulphuric acid re-formed the sulphate. 

 It possessed energetic reducing properties, reducing Fehling's 

 and ammoniacal silver solutions in the cold, gave a dense red 

 precipitate with neutral copper sulphate, and formed crystalline 

 compounds with aromatic aldehydes and ketones. It is very 

 seldom that chemistry is enriched by the discovery of a new gas, 

 and the intrinsic value of the isolation of amidogen to both 

 oi^anic and inorganic chemistry renders the communication 

 of Dr. Curtius one of exceptional and of far more than passing 

 interest. 



Measurements have lately been made by Messrs. A. von 

 Eltingshausen and W. Nernst, upon the Hall effect manifested 

 -m different metals. They have found that tellurium far sur- 

 passes bismuth in its power, hence they think that the Hall 

 effect is connected with the thermo-electric properties of the 

 metals. The effect is least in tin. Taking this as unity, 

 the effects in other metals are relatively as follows : pla- 

 tinum, 6 ; copper, 13; gold, 28; silver, 21; palladium, 29 ; 

 cobalt, 115; iron, 285 ; nickel, 605 ; carbon, 4400; antimony, 

 4800; bismuth, 252,500 : tellurium, 13,250,000. The sign of 

 the effect is positive in the case of cobalt, iron, steel, antimony, 

 and tellurium, also lead, zinc, and cadmium. It is negative in 

 all the others. 



The mining engineer, M. Dahll, who has been examining 

 the north of Norway on behalf of the Norwegian Government, 

 states in his Report that all the rivers in the interior of Finn- 

 marken, a district of fifty Norwegian .square miles, carry gold. 

 The metal is found in sand contained in little hollows, which 

 by their shape prevent its being washed away by the water. The 

 weight of the gold grains varies from 10 milligrammes to X gramme. 

 Platinum is also found occasionally. 



During the cutting of peat in a moss at Vevang, near the 

 town of Christiansund, in the north-west of Norway, the work- 

 men recently dug out a log of oak over 12 feet in length, and 

 about 4 feet in diameter. It was found at a depth of 9 

 feet. The trunk and root of a great oak-tree were unearthed in 

 the same moss .some years ago, so we may conclude that there 

 was once an oak forest in this spot. The remains of the oak 

 were found below a layer in the bog in which remains of firs are 

 often found. 



In the new number of the Proceedings of the Geologists' 

 Association there is a paper by Dr. H. Hicks on the explora- 

 tions which he, in conjunction with others, has carried on in the 

 Ffynnon Beuno and Cae Gwyn Caverns in North Wale-;. He 

 has no doubt whatever as to the accuracy of the conclusions 

 presented by him in his previous papers on the subject. " I 

 am," he says, "perfectly convinced by the evidence found 



during the exploration of these caverns that they must have been 

 occupied by man and the animals before the climax of the 

 Ice age ; also that the thick stalagmite was formed some time 

 during that age ; that this was broken up by marine action 

 during the submergence ; and that the caverns were afterwards 

 completely covered over by materials deposited. fiom floating ice. 

 There seems, therefore, to be every reason to suppose that man 

 and the so-called Pleistocene animals arrived in this country in 

 advance of the glacial conditions, and that their migrations 

 were mainly from northern and north-western directions. " 



The first number of the Technology Quarterly has been sent 

 to us. This new American periodical is published by a Board of 

 Editors chosen from the senior and junior classes of the Massa- 

 chusetts Institute of Technology, representing, as far as possible, 

 all the departments of the Institute. A large amount of original 

 work is done in the Institute every year by advanced students, 

 and it is thought by the editors that the Quarterly will be an 

 acceptable journal if it contains nothing more than the results 

 of the original investigations made in the chemical, physical, 

 mining, mechanical, and biological laboratories, and also in the 

 departments of civil engineering and architecture. But it is 

 expected that the alumni of the Institute will be glad of this 

 medium for recording their investigations and the results of their 

 practical work. Among the contents of the present number are 

 articles on " The Control of Rivers and the Prevention of 

 Floods," "The Efficiency of Small Electromotors," " The Use 

 of the Aneroid Barometer in Western Massachusetts by the 

 U.S. Geological Survey," and "The Constitution of Benzol." 



The additions to the Zoological Society's Gardens during the 

 past week include two Macaque Monkeys {Macacus cynomolgus) 

 from India, presented respectively by Mrs. Slatter and Mrs. 

 Beeston; a Lesser White-nosed Monkey {Cercopithecus petaur- 

 ista) from West Africa, presented by Miss Kate Wood ; a Grey 

 Ichneumon {Herpestes griseus) from India, presented by Miss 

 Dudding ; a Common Squirrel (Sciurus vulgaris), British, pre- 

 sented by Mrs. Dick ; a Virginian Deer {Cariacus virginianus) 

 from North America, presented by Mr. Tom Jay ; three 

 Keiirels {Tin/iunculus alatidarius), British, presented by Dr. J. 

 W. Trentler ; two Blue Titmice {Parus civruleus), British, pre- 

 sented by Mrs. Francis L. Barlow ; a Blue-eyed Cockatoo 

 {Cacatua ophthalmica) from New Britain, presented by Mr. W. 

 H. Fellows ; four Horned Vipers ( Vipera cornuta), three Dwarf 

 Chameleons [Chanucleon puinilus), a Many-spotted Snake (C^w- 

 ttrlla vmltimaculata), a Rufescent Snake {Leptodira rufescens) 

 from South Africa, presented by the Rev. G. H. R. Fisk, 

 C.M.Z.S. ; a Crowned Horned Lizard {Phrynosoma coronatum) 

 from California, presented by Mr. Dufil" Gordon ; a Pig-tailed 

 Monkey [Macacus nemestrinus) from India, four Herons {Ardea 

 cinerea), six Night Herons (Nyclicorax griseus), European, 

 deposited; a West African Python {Python sclnt) from West 

 Africa, purchased ; a Mesopotamian Fallow Deer {Dania meso- 

 potimica), two Japanese Deer {Cer-jus sika), two Collared Fruit 

 ^■\\.% {Cynonycteris collaris) born in the Gardens; two Yellow, 

 legged Herring Gulls {Larits cachinnans) bred in the Gardens. 



OUR ASTRONOMICAL COLUMN. 

 The Great Southern Comet, 1887 «.— Mr. Chandler 

 continuing his researches on the orbit of this comet (referred tc 

 in last week's Nature), gives, in No. 157 of the Astronomical 

 Journal, the following elements deduced from the Cape and 

 Adelaide observations published in the Monthly Notices foi 

 March last : — 



T - 1887 January 11-230 G.M.T. 



<" = 63 36 o ^ 

 Q, = 337 428 

 I - 137 00 

 log q = 773892 



True Equinox. 



