fan. 29, 1 885] 



NA TURE 



3°S 



who also wander up to the snow line. At a height of 

 13,000 feet lie saw three elephants, and at night the shrill 

 trumpeting of these animals could be heard round the 

 station. On October 18 he found himself, most unwil- 

 lingly, obliged t" leave the elevated settlement and re- 

 turn to Taveita. The relatively great cold they had ex- 

 perience'! had reacted very unfavourably on his men's 

 health, and he feared that a longer delay might render 

 them quite unfitted to carry burdens. He intended, however, 

 to make his return journey entirely through a new and hitherto 

 untraversed country, and this project somewhat consoled him 

 for leaving the summit of Kilimanjaro still unconquered. Their 

 downward journey, part of the way through trackless bush and 

 dense dank forest, was not without adventure and some reward 

 in scenery of great beauty. The average elevation of this 

 country was between 8000 and 7000 feet, and the temperature 

 consequently almost cool, ranging from 43" at night to Jo° in 

 the mid-day warmth. After some four hours' walking from 

 their camp they crossed the long ridge that marked the southern 

 flank of Kimawenzi, and began to descend the eastern slope of 

 the mountain. Soon they emerged on a kind of heath-like 

 country, and then looked forth on a splendid view stretching 

 from Mwika to the mountains of Bura and Ukambani (the 

 Kiulu range), with Jipeon one hand and the River Tzavo on 

 the other. After some enjoyable excursions from his settlement 

 a' Taveita, finding that his funds would not support the expe- 

 dition beyond the end of November, he made a rapid journey 

 to the coast by way of Pare, Usambara, and the Rufu river to 

 Pangani. At Zanzibar, finding there were no fresh funds to 

 enable him to return to Kilimanjar >, he paid off the last of his 

 faithful followers, many of whom had accompanied Thomson 

 on his great journey, and took his passage on the British India 

 steamer to Suez in quite a sulky frame of mind, as s jrry to leave 

 his beautiful mountain as many people are to quit England. 

 Travelling overland from Suez, he arrived in London not much 

 more than six weeks after he had caught his last glimpse of the 

 snows of Kilimanjaro. 



A SCANDINA VI AN LAND OF OPHIR 



W 1 



'E learn from Naturen that the little island in the Hardanger 

 Fjord, known as Bommeloen, which two years ago was an 

 uninhabited and desolate spot, is now a busy scene of extensive 

 gold-digging. Numerous English artizans and Norsk brick- 

 layers and carpenters have for months been actively engaged in 

 boring and sinking shafts into the 10 :k, and in preparing houses 

 and shelter for the men and machinery that have been drawn 

 hither by the report of the discovery in 1882 of gold in the 

 Storhangen mine. This discovery had been anticipated in 1862 

 by the find of a piece of pure gold, which was at once deposited 

 in the mine-alogical museum of Christiania, wdiere it has since 

 remained apparently unheeded, although the place and time at 

 which it was found are duly marked on the corresponding label. 

 After twenty years gold was again found in 1S82, at the 

 Storhangen mine, which was then being worked for copper 

 ore. The result of this discovery was the purchase, in 1883, of 

 thi works l>. an English firm, trading under the title of the 

 11 r Gold ing Company, which is worked under the scien- 

 tific direction of Mr. Murchison. Considerable amusement 

 seems so have been created among Norsemen by a somewhat 

 ambiguous statement, set forth in the Company's circulars, which 

 oracularly announces that "the gold finds at Bommeloen are 

 cither Nature's greatest success or her greatest illusion " ! 



The geological formation of Bommeloen is similar to that of 

 other auriferous rocks, the gold being found in quartz, which 

 occurs in strata never .note than six feet thick, although of con- 

 siderable extent, and generally underlying green (chloritic) schist. 

 The greenstones "f the island differ from those found in other 

 parts "I N'i way. and contain glass and various typical vulcanic 

 products. 



The operations of the Oscar Mining Company have given a 

 new stimulus to the search for gold in Norway, and we learn 

 that Herr Bakke, Inspector of Mine • at Trondhjem, lias officially 

 reported the discovery of virgin gold in a piece of chloritic slate 

 from Stegen in Nordland, while it is authoritatively stated that 

 gold ha been found within the last year or two at Sveen in the 

 Bergen-Amt, and also near Stavanger. In the latter case the 

 discoverer, Nils Berg, an old experienced Australian gold- 

 digger, washed the gold fro 11 the mud remaining at the bottom 

 of a shaft that had been sunk in a copper mine. 



SCIENTIFIC SERIALS 

 Wiedemann's Annalen, vol. xxiv. January 1SS5 — O. Leh- 

 mann, on the melting-points of bodies in contact, and on the 

 electrolysis of solid iodide of silver. A remarkable paper, 

 accompanied with an elaborate plate describing phenomena of 

 crystallisation observed chiefly with microscope at limiting edge 

 of two crystallisable liquids or solutions. Iodide of silver pre- 

 sents certain closely-related phenomena under electrolysis, both 

 in molten and in solid condition. Regular crystalline iodide of 

 silver conducts an electric current, the silver being carried in the 

 direction of the negative current through the crystal without its 

 structure being disturbed. In its electrolysis, however, there 

 appears a streaking in the direction of the flow of the current.- — 

 \V. von Bezold, on a new kind of cohesion-figures. These 

 experimental researches relate to the quasi-dendritic forms ob- 

 served when one liquid descends through another. — L. Boltz- 

 mann, on the possibility of founding a kinetic theory of gases on 

 attractive forces alone. This is an attempt to dispense with 

 Maxwell's hypothesis that molecules repel one another in the 

 inverse fifth power of the distance, which he framed to account 

 for the apparent perfect elasticity exhibited by molecules of 

 gases. Boltzmann proposes a new theory, based on attraction, 

 very similar to that recently independently propounded by Sir 

 W. Thomson (Nature, August 28, 1884).— O. Chwolson, on 

 the calibration of the plug-rheostats of Siemens and Halske. 

 This discusses corrections for the resistance of connecting-pieces, 

 &c. — F. Kohlrausch, the electric conductivity of water distilled 

 in vacuo. A column of pure water I metre long and of 1 square 

 millimetre section has a resistance of about 4 X io 10 ohms. — G. 

 Kirchhoff, on the change of form which an elastic body 

 experiences when it is magnetically or dielectrically polarised. 

 This paper, originally published in the Pins, dings of the Berlin 

 Academy, deals analytically with the phenomenon of electro- 

 striction investigated by Lorberg and others. — A. Schuster, on 

 the discharge of electricity through gases. Treats of certain 

 points in dispute between the author and Profs. Goldstein and 

 E. Wiedemann. The author pronounces in favour of the view 

 that all the phenomena of effect of magnetism, &c, upon the 

 discharge of the negative electrode may be explained if it be 

 admitted that the negatively-charged portions of the gaseous 

 molecules are driven off from the kathode. — E. Goldstein, on 

 electric conduction in the vacuum. Discusses some experiments 

 in which a carbon filament lamp was employed ; the filament 

 forming one electrode, a platinum wire being inserted through 

 the glass to serve as another electrode for the discharge, which 

 was obtained, without an induction-coil, with electromotive forces 

 of about 300-350 volts. — Werner Siemens, contributions to the 

 theory of magnetism. Describes experiments on partially-closed 

 magnetic circuits of iron, giving rise to the opinion, that the 

 harder a specimen of iron is, the greater is the value of the 

 magnetising force at which the maximum of permeability is 

 observed. Also, the magnetic resistance of air is from 480 to 

 500 times as great as that of iron. — II. Hertz, on the dimen- 

 sions of unit of magnetic pole strength in different system's of 

 measurement. — E. Ketteler, the optical constants of magnetic 

 media. Develops equations rela'ingto Kundt's recent magneto- 

 optic observations. — E. von Fleischl, the double refraction of 

 light in fluids. Proves that in optically-active liquids the rota- 

 tion is due to the existence of double refraction. Double- 

 refracting liquids have no optic axis, and the wave-surface con- 

 sists of two concentric spherical sheets. — W. von Voigt, on the 

 measurement of the refractive indices of absorbing media. 

 Recommends the prism method as more accurate than the total- 

 reflection method. — W. von Voigt, on the theory of reflection 

 and refraction at the boundary of crystalline media. New 

 equations based on the author's theory of the reactions between 

 matter and ether in transparent media, and leading to same con- 

 clusions as Kirchhoff's older theory. 



Journal de Physique, November, 1884. — J. Jamin, on hygro- 

 metry. The author proposes to substitute for the "relative 

 humidity " a new coefficient termed the " hygrometric richness," 

 which is the ratio of the actual pressure of aqueous vapour of the 

 air to the difference between the total atmospheric pressure and 

 the actual vapour pressure. The substitution appears to be both 

 rational and instructive. — Ch. Riviere, essay on cooling power 

 of gases. Confirms formula of Dulong and Petit up to 400 C, 

 but above that temperature the observed values are lower than, 

 the theoretical. Also appears to prove that at very low pres- 

 su~es cooling power is in lependent of tlu chemicil c imp isition 



