May t I, 1 905 J 



NA TURE 



M 



on the Uelle in the west, to Lado and Dufile on the Nile. 

 In the whole of this region, the only post-Primary rocks 

 met with, other than those of comparatively modern 

 alluvial origin, were chocolate-coloured shales (Buta Shales) 

 and sandstone, and an Oolitic limestone, on the extreme 

 west. From the Lipodongu Falls on the Rubi, and thence 

 through Poko to Rungu, on the Bomokandi River, none 

 but granitic rocks (gneisses) were observed. Along the 

 Uelle, from Bima to Bomokandi, the same rocks were seen. 

 In the centre of the region mica-schists, quartzites, and 

 similar metamorphic rocks replace the granite wholly or in 

 part. A noticeable feature here is the presence of a range 

 of isolated hills, composed almost completely of great beds 

 of magnetite and ha2matite occurring in the schistose series. 

 In the south-eastern portion of the region visited, between 

 the Uelle-Kimbali and Bomokandi rivers, a great plutonic 

 massif is laid bare in the mountainous district of Arebi. 

 The plutonic massif itself contains microclinic gneiss, and 

 abundant diabasic rocks, and the same rocks in all stages 

 of dynamo-metamorphism. On the boundary between the 

 Congo State and the Bahr-el-Ghazal, several hills made up 

 of rocks of coarse gneissose and schistose character are 

 described ; some of these rocks are rich in tourmaline, 

 kyanite. and garnet in large crystals. From the region of 

 the Enclave de Lado and the western side of the Nile 

 between Lado and Dufile, mica-schists, quartzites, and 

 microcline-gneisses are described. The alluvium of a large 

 part of the Uelle is covered, on the higher ground, by a 

 deposit of limonitic conglomerate ; in places this may be 

 due to the decomposition in situ of the alluvium, but in the 

 neighbourhood of the iron-mountains a sort of passage may 

 be seen between a conglomerate of fresh iron-ores and the 

 more general type of limonitic conglomerate (laterite?). 



Paris. 

 Academy of Sciences. Nfay i. — M. Troosr in the ch.^ir. — 

 New researches on chemical combination : M. Berthelot. 

 Various substances were sealed up in fused quartz tubes, 

 heated for one hour at 1300° C. in an electric furnace, and 

 suddenly cooled by dropping into water. Nitrogen and 

 hydrogen gave no trace of ammonia ; ammonia was com- 

 pletely split up into its constituents, and the stability was 

 not increased by the presence of hydrochloric acid. The 

 latter gas, heated alone, was not decomposed, and hydrogen 

 sulphide behaved similarly if the cooling was slow, but 

 showed evidence of dissociation into hydrogen and sulphur 

 with instantaneous cooling. — On the permeability of tubes 

 of fused silica : M. Berthelot. At the ordinary tempera- 

 ture, no hydrogen will pass through the walls of a 

 fused quartz tube, even into a barometric vacuum, and 

 even at 600° to 800° no appreciable amount passes 

 through. At 1300° C, on the other hand, the amount 

 transpired is considerable. Neither hydrochloric acid nor 

 carbon dioxide get through at 1300° C. ; the transpiration 

 of nitrogen is not sensible at 600° C, very slight at 

 1000° C, becoming marked at 1300° C. to 1400° C. Some 

 preliminary experiments with glass at lower temperatures 

 appear to show similar effects, and these observations are 

 being continued. — The action of mercuric iodide on 

 sulphuric acid and on the sulphates of mercury ; Alfred 

 Ditte. — On the earthquake of April 20 : M. Mascart. 

 The seismograph at Bagneres-de-Bigorre showed horizontal 

 vibrations at 2h. im. 20s., whilst the same oscillation was 

 indicated at Grenoble at ih. .sqm. 15s., a difference of time 

 corresponding to the rate of transmission through the 

 ground. — On the triboluminescence of arsenious acid : M. 

 Guinchant. The light given off by arsenious acid is due 

 to the breaking and transformation of the crystals after 

 their formation. The radiations are actinic, and are with- 

 out any effect on the electroscope. Similar phenomena 

 taking place during the reduction of hypochlorites and 

 hypobromites are described, the effects in this case being 

 attributed lo the production and decomposition of haloid 

 compounds of nitrogen. — On the physical impossibility of 

 putting in evidence the motion of translation of the earth : 

 P. Lang:evin. In a discussion of an experiment by 

 Trouton and Noble it is proved that it ought to give a 

 negative result for all orders of approximation and what- 

 ever system of suspension be employed for the condenser. 



NO. 1854, VOL. 72] 



— On the heat of vaporisation of liquefied gases : E. 

 Mathias. — Heat in the displacement of a capillary system : 

 M. Porsot. — On the difference in temperature of bodies 

 in contact : E. Rogrovski. Fine wires of different diameters 

 were heated by an electric current, and cooled by water 

 flowing at known rates. The temperature of the wire was 

 measured by means of its electrical resistance, and the 

 difference of temperature between the wire and the cooling 

 water determined as a function of the rate of flow of the 

 water and of the diameter of the wire. — The preparation 

 of anhydrous chlorides of the metals of the rare earths : 

 Camille Matignon. The solid material obtained by the 

 evaporation of the solution of the oxide in hydrochloric 

 acid is heated in a current of chlorine and hydrochloric 

 acid gas charged with the vapours of chloride of sulphur. 

 It is possible to obtain in this way very rapidly either 

 large or small quantities of anhydrous chlorides. Par- 

 ticulars are given with analyses showing the purity of the 

 products, of the chlorides of lanthanum, neodidymium, 

 praseodidymium, samarium, and yttrium. — On caesium 

 amide : E. Rengade. The amide is prepared by the 

 action of dry ammonia upon the fused metal at 120° C, 

 the purity of the product being fixed by the determination 

 of the amount of hydrogen evolved. The amide dissolves 

 readily in liquid ammonia, and the solution absorbs oxygen 

 at —60° C. giving a precipitate, the hydro.xide and nitrite 

 of cfesium being formed, together with ammonia. — On a 

 new reagent for potassium : Eugenio Pinerua Alvarez. 

 The reagent proposed is a 5 per cent, solution of sodium 

 amido-naphthol sulphonate. — On the conditions of develop- 

 ment of the mycelium of Morchella : G. Fron. The 

 myceliuni of this edible mushroom requires for its strong 

 growth plenty of hydrocarbon food, inulin and starch being 

 especially favourable ; the mineral food is of less import- 

 ance. — Calcium nitrate in agriculture : E. S. Bellenoux. 

 The author proposes to replace nitrate of soda by the 

 nitrate of calcium, and gives results of comparative trials 

 of the two showing the superiority of the latter as a 

 manure. — The variation of the osmotic pressure in muscle 

 caused by contraction : St^phane Leduc. It is shown ex- 

 perimentally that an elevation of the osmotic pressure in 

 a muscle is a consequence of contraction, the rise of the 

 pressure being more marked as the stimulations are more 

 prolonged. — The variations undergone by glucose, glycogen, 

 fat, and soluble albumens in the course of the metamor- 

 phoses in the silkworm : C. Vaney and F. Maignon. — 

 On a combination of mcthaemoglobin containing fluorine : 

 H. Ville and E. Derrien. In a previous paper the authors 

 have shown that the addition of fluorine compounds to a 

 solution of methEemoglobin causes a marked change in the 

 absorption spectrum, and they were thus led to the conclusion 

 that a definite compound might possibly be produced. This 

 compound has been isolated in the crystalline form, details 

 of its preparation and properties being given in the present 

 note. — Philocatalase and anticatalase in animal tissues : 

 F. Battelli and IWlle. L. Stern. — On the action of formic 

 acid in nervous diseases accompanied with trembling ; E. 

 Clement. The use of formic acid has been attended with 

 great success in certain cases. — The volcanic regions 

 traversed by the Sahara expedition : F. Foureau and Louis 

 Gentil. 



New South Wales. 

 Linnean Society, March 2q.— Mr. T. Stfel, ) r sidenf, in 

 the chair. — The botany of north-western New South Wales : 

 F. Turner. The characteristics of the indigenous vegeta- 

 tion and the exotic weeds of the country lying between the 

 New South Wales-Queensland border and 33° S. lat. , and 

 147° and 151° 20' E. long., are discussed. The census of 

 the phanerogams and vascular cryptogams given comprises 

 a total of 452 genera and 1137 species. — Contribution to 

 our knowledge of the physiology of the pancreas : H. G. 

 Chapman. The conclusions arrived at in this paper, 

 which is a preiiminarv communication, ma}* be summarised 

 as follows : — (i) secretins from the echidna, wallaby, 

 .Australian water-tortoise, and ibis are active upon the dog 

 in causing a flow of pancreatic juice ; (2) secretin does not 

 appear to cause pancreatic secretion in the echidna ; (3) the 

 flow of pancreatic juice produced by pilocarpine is inhibited 

 bv atropine, while the flow produced bv secretin is not so 



