February 17, 1898] 



NA TURE 



381 



mental subjects are practical ; and the number of students who 

 took practical work is as follows : Inorganic Chemistry, 

 15,169 ; Magnetism and Electricity, 2694 ; Sound, Light, and 

 Heat, 1793; Organic Chemistry, 1538. The remaining 

 practical subjects— human physiology, general biolog}', zoology, 

 botany, and metallurgy — divided 1852 students between them. 

 There are now 169 Schools of Science in which organised 

 courses of study are taken in connection with the Department, 

 and the number of students attending them is 20,879. 



SCIENTIFIC SERIALS. 



The most important contribution to Himmel und Erde for this 

 month is a long paper on the terminal moraines of North Ger- 

 many. The other papers comprise one in which is given the 

 conclusion of a lecture by Dr. Drygalski on Greenland, dealing 

 mainly, in this part, with the habits and customs of the Esqui- 

 maux ; and another by Herr G. von Gleicke treating of the exist- 

 ence of an intra-mercurial planet or planets, generally surveying 

 the various theories that have been put forward to explain the 

 motion of the perihelion of Mercury. The only result that appears 

 certain in the paper is the practical confirmation of the reality of 

 the motion, originally determined by Le Verrier. The presence 

 of a single planet or of a ring of meteoric matter ; the existence 

 of an unknown satellite of the planet itself, or an ellipticity in 

 the figure of the sun ; an alteration in the expression of the law 

 of gravitation or the introduction of terms suggested by electro- 

 dynamic considerations ; all seem to oflFer insuperable objections, 

 or to be based on pure empiricism. The enigma is not solved 

 yet. The subjects to which the shorter notes refer have generally 

 been mentioned in these columns. They include some account 

 of the Greenland Meteor ; the sinking of the surface of the earth 

 in the neighbourhood of the Canadian lakes, and its effect on 

 the Niagara Falls ; the depth of the sea and the determinatioij 

 of ocean currents around Australia derived from floating 

 bottles. A short notice is also added of a proposed 

 attempt on the part of MM. Godard and Surcouf to 

 reach the North Pole by means of ballooning. The expedition 

 would start in the summer of 1898, selecting Spitsbergen as a 

 base of operations. The peculiar feature of the attempt seems 

 to consist in carrying twelve small balloons, filled with hydrogen 

 to serve as a gasometer to supply the main balloon, which 

 is of gigantic dimensions, with the gas which may leak or waste. 

 M. Godard counts on spending sixty days aloft, and to carry 

 with him the means of support of no less than seven people, 

 among whom will be found a chemist, a meteorologist, and a 

 physician. 



Memoirs of the Catuasian Branch of the Russian Geo- 

 graphical Society, vol. xviii. — On the distribution of precipitation 

 in Caucasia during the spring and summer of 1894, by A. 

 Woznesensky, with four maps. — Journey in the Chernomorsk 

 district, in 1894, by N. Alboff ; with a map (on the scale of seven 

 miles to an inch) of the Chernomorsk district and the western 

 jjart of the district of Sukhum ; and botanico-geographical 

 researches in Western Transcaucasia, by the same author, being 

 a continuation of his paper inserted in a preceding volume of 

 his Alemoirs. In this paper two important excursions across 

 the main ridge of Abhasia are described. The flora of the 

 limestone-mountains having been the special subject of studies, 

 it is dealt with in detail. The rare new species Amphoricarpus 

 elegans, which was formerly found at two places only of 

 Abhasia and Mingrelia, was met with in thousands. A bush- 

 like Campanula, which M. Alboff considers as a new species, 

 was found and was named C. regina for its rare beauty. 

 Numbers of other rare species were found. Detailed lists of 

 the limestones' fauna in Abhasia and Mingrelia are given. In 

 addition to the glaciers previously discovered on the northern 

 slope, a hanging glacier was found on the southern slope. 

 Very interesting remains of the ancient population of the 

 region are mentioned. — On the Kumyks, anthropological sketch 

 by J. Pantukhofif. The paper contains a sketch dealing with the 

 possible origin of this Tartar stem, anthropological measure- 

 ments made by the author, and a comparison of the same with 

 measurements on other Caucasian stems. — The Pshaves and 

 their land, by D. Khizanachwili. — A journey in the central por- 

 tion of the Mountain-Chechnya, by Madame A. Rossikoff, with 

 a map three and a half miles to the inch. Detailed and lively 

 account of a journey in that imperfectly known part of Dag- 

 hestan, the seat of Shamil's wars. — Statistical description of, 



NO. 1477. VOL. 57] 



and statistical data relative to, the provinces of Baku, Kars, 

 Erivan, Daghestan, and Elisabethpol. — On the condition of 

 glaciers and of the lakes on the northern slope of Central 

 Caucasus, by K. Rossikoff. — In a very interesting appendix we 

 find (i) a beautiful atlas of eight ethnographical maps of Trans- 

 caucasia, one for each separate province, on the scale of thirteen 

 miles to an inch (it is the work of E. Kondratenko) ; (2) a 

 map of the distribution of the Armenian population in Asia 

 Minor, on the basis of V. Cuinet's data, 1890-94, accompanied 

 by a paper by General Zelenyi and Colonel Sysoeff ; and (3) 

 the distribution of Armenian populations in Transcaucasia. 



We have received the number of the Irish Naturalist for 

 February, and are always glad to say a word on behalf 

 of these local natural history journals, which have done so 

 much to encourage the early enthusiasm of many who have 

 afterwards become eminent naturalists. In the present num- 

 ber Mr. Allan P. Swan describes and figures a new species 

 of Leptolegnia, L. bandoniensis, belonging to the Sapro- 

 legniacece. 



The Journal of Botany, in its numbers for January and 

 February, still continues to cater chiefly for descriptive 

 and "critical" botanists. Mr. F. Townsend describes and 

 figures a new species of Euphrasia, E. canadensis, from the 

 neighbourhood of Quebec ; and Miss Ella M. Tindall en- 

 riches British Hepaticse with a species new to science, Fos- 

 sombronia Mitte7iii, from North Devon, which is also figured 



SOCIETIES AND ACADEMIES. 



London. 



Royal Society, January 20. — " Fergusonite, an Endo- 

 thermic Mineral." By William Ramsay, Ph.D., LL.D.^ 

 Sc.D., F.R.S., and Morris W. Travers, B.Sc. 



The mineral fergusonite, discovered by Hartwall, occurs in- 

 felspar and mica deposits, in the same manner as most of the 

 rare Norwegian minerals, such as euxenite, orthite, samarskite, &c. 

 The position in which such minerals are found, embedded in masses 

 of felspar, or encrusted with mica, leaves the question of their 

 origin an open one. Whether they are deposited in the felspar 

 by water, or whether they are contemporaneous with the felspar, 

 is a matter of speculation. Fergusonite is a black lustrous 

 mineral, not unlike obsidian in outward appearance, but of 

 considerably higher density. Seen under the microscope, even 

 with the highest power, there is absolutely no sign of crystalline 

 structure, though in thin slices the substance is translucent, and 

 transmits yellow-brown light. It is, however, macrocrystalline, 

 occurring in quadratic sphenoids. It is quite homogeneous, and 

 displays no sign of cavities. Like similar minerals, it contains 

 helium, which is expelled on the application of heat. 



But this mineral presents a peculiarity, which has led us 

 to publish this note. When heated to a temperature not 

 exceeding 500° or 600°, it suddenly becomes incandescent, 

 and evolves much of its helium ; while its density decreases. 



The analysis of the mineral was kindly undertaken by Miss 

 Emily Aston, to whom we desire to express our indebtedness. 



It showed that fergusonite is mainly a niobate of yttrium,, 

 containing oxides of uranium, but in no great quantity. 



The gases evolved by the incandescence of nearly 5 grams 

 (4-852) of the mineral, heated in a vacuous tube, were analysed 

 and found to consist of helium, hydrogen, carbon dioxide, and 

 nitrogen. 



The density was determined before and after heating. Great 

 care was taken to make sure of the absence of air-bells, by 

 warming the powdered mineral under water in a vacuum, before 

 weighing it. 



Density before heating 5 61 9 



after „ 5'375 



It is thus seen that the mineral loses density on incandescence. 



The amount of heat lost by this curious mineral in parting 

 with its helium was determined. The plan of operation was to 

 burn in oxygen a known weight of hydrogen, ascertained by 

 measuring it, under a small platinum crucible, in a calorimeter. 

 The rise of temperature was noted. This operation was re- 

 peated several times, so as to standardise the calorimeter. Some 

 grams of mineral were then placed in the crucible, and the 

 operation was repeated ; the heat evolved by the incandescing 

 mineral added itself to that from the burning hydrogen, and the 



