June 26, 1890] 



NATURE 



215 



through the whole extent of peridotite and serpentine rocks, 

 and inferentially in the drifts derived therefrom. The President 

 noted the interest attaching to the gradual development of our 

 knowledge of native iron of terrestrial origin. Prof. Judd was 

 glad to have the present opportunity of removing a misconcep- 

 tion that had arisen concerning this mineral. In bringing the 

 matter before the Society on a previous occasion he dwelt upon 

 the facts of special geological interest, and Mr. Skey's name 

 was not mentioned in the few lines placed on record in the Pro- 

 ceedings. No attempt, however, had been made by Prof. 

 Ulrich to claim the discovery of this mineral, though he ap- 

 peared to have been the first to record its peculiar occurrence in 

 the ultrabasic rocks. In the South Island was the well-known 

 chromite-bearing olivine rocks of the Dun Mountain, but the 

 rock now described was in a distant part of the same island. 

 An interesting series of serpentines derived from peridotites 

 has been sent over by the author, and these specimens contain 

 the " Awaruite." A number of garnets and chlorites, with 

 chrysotile, talc, and magnetite, have been found in the Red 

 Hills. He was not aware that any " Awaruite" had been dis- 

 covered in the peridotite ; but this was probably due to the 

 softer nature of the serpentine, where it could be more easily 

 detected. He had recently heard that one of the serpentines of 

 Norway had yielded a similar alloy. 



Edinburgh. 



Royal Society, June 2. — Sir Douglas Maclagan, Vice- 

 President, in the chair. — Prof. Crum Brown read a paper on 

 the relation of optical activity to the character of the radicals 

 united to the asymmetric carbon atom. He stated that — if we 

 denote the optically active compound by the symbol C(ABrA) — 

 where C denotes the carbon atom, and A, B, r, A denote the 

 radicals arranged in order of a hitherto undetermined quantity, 

 K — any replacement of one of the radicals by a new one which 

 changes the order as regards K alters the sense of the optical 

 activity. Suppose, for instance, that as seen from A the values 

 of K for B, r, A are in ascending order. If we substitute for r 

 an atom whose K is greater than that of A, the order will now 

 be B, A, r', which is left-handed if that of B, r, A was right- 

 handed. Thus (assuming that increase of mass is accompanied 

 by increase of K), he finds that in a number of such compounds 

 the alteration indicated produces a substance in which the direc- 

 tion of rotation of the plane of polarization of light is reversed. 

 — Dr. H. R. Mill read a paper on the mean level of the surface 

 of the solid earth, in which he showed that, from Dr. John 

 Murray's calculations, the general level of the lithosphere was 

 at a depth of 1400 fathoms beneath mean sea-level. More 

 recent explorations show that the oceanic depths are deeper and 

 more extensive than was formerly supposed, so that the mean 

 sphere-level — the surface of a shell which cuts the slope between 

 the elevated and depressed region of the earth's surface in such 

 a manner as to leave a volume of elevated material above it 

 exactly equal to the volume of the depressed region beneath it 

 — appears to lie close to a depth of 1700 fathoms. The contour 

 line of 1700 fathoms of ocean depth divides the earth's surface 

 into two equal areas — one of depression, the other of elevation. 

 This remarkable coincidence shows that the portions of the 

 elevated half of the lithosphere projecting above mean sphere- 

 level would just suffice to fill the hollow beneath mean sphere- 

 level of the depressed half. Dr. Mill also pointed out that 

 round the edge of the great three-armed northern elevated mass 

 the slope to the depressed area was so steep that the outlines of 

 tlie iooo>and 2000 fathom contours follow the coast-line very 

 closely ; but the Antarctic elevation rises from the bed of the 

 depression with an extremely gentle slope. — Mr. J. Crockett 

 communicated an account of Weierstrass's contributions to the 

 calculus of variations. — Mr. John Anderson gave accounts of 

 the recent Louisville tornado, and showed a barometric record 

 made in its neighbourhood. The barometer fell suddenly to the 

 extent of about one-tenth of an inch, and again instantly rose as 

 the tornado passed. 



Paris, 



Academy of Sciences, June 16.— M. Hermite in the chair. 

 — On the ordnance survey of France, by M. Maurice Levy. In 

 commenting upon the work undertaken by the Geodetical Com- 

 mission, "M. Levy notes that two kinds of documents will 

 be published — one' to contain an account of the methods of 

 calculation and corrections which have been employed, as 

 well as the description of the instruments used ; the other 

 to be a graphical r^pa-toire of the levels determined — and in 



NO. 1078, VOL. 42] 



presenting an account of the first series of operations, some- 

 explanation of the work is given. — Theory of the permanent 

 movement produced near the widened opening of a fine 

 tube ; application to the second series of Poiseuille's ex- 

 periments, by M. J. Boussinesq. — Calculation of the successive 

 temperatures in an indefinite homogeneous and athermanous 

 medium which is in contact with a source of heat, by the .^ame 

 author. — On the various isomeric inosites and their heat of 

 transformation, by M. Berthelot. The author finds that in 

 dextrorotatory inosite, dehydrated and having the formula 

 CfiHjjOfi, dissolved in 300 c.c. of water at I7°'9, the heat 

 absorbed by i molecule is - 2*05 calories. Laevorolatory inosite 

 similarly treated gives - 2*03 calories. On mixing the two 

 liquids no rise or fall of temperature was observed. It is 

 therefore concluded that two symmetrical inosites do not show 

 any signs of combination when in solution. Four grammes of 

 neutral inosite were dissolved in 300 c.c. of water at 18°. The 

 rate of solution was slower than that of the active inosites, and 

 the heat developed was - 3 "87 calories. This heat of solution is 

 negative and greater than that of either of the active inosites. 

 The three corresponding tartaric acids give the same results. — 

 Variation of the elasticity of glass and of crystal with tempera- 

 ture, by M. E. H. Amagat. It appears from the experiments 

 that the variation increases with the temperature ; it is a little 

 greater for glass between 100° and 200° than between 100° and 

 0°, and considerably greater in the case of crystal ; and it seems 

 probable that the variation would increase more and more in 

 value with still higher temperatures. — On a new property of 

 luminous waves, by M. Gouy. — Characteristic equation of 

 hydrogen, by M. Ch. Antoine. — On the variation of temperature 

 with altitude in cyclones and anticyclones, by M. Marc 

 Dechevrens. From a series of observations the law is formulated 

 that " at sea-level and in air, at an altitude less than 1000 

 or 1200 metres, the temperature in a vortex varies inversely 

 as the pressure, whilst in air at greater altitudes it varies 

 directly as the pressure. In the latter case the temperature 

 has a minimum along the axis of the cyclone and a maxi- 

 mum on the perimeter of the depression ; a maximum also 

 occurs along the axis of an anticyclone." — On the combina- 

 tions and reactions of the gases ammonia and phosphor- 

 etted hydrogen with the halogen compounds of arsenic, by 

 M. Besson. The compounds AsBrg.sNHj ; ASCI3.4NH3 j 

 ASI3.4NH3; and 2ASF3.5NH3 are described, and the products 

 of their decomposition indicated. — On a new method of forming 

 crystalline oxychlorides of the metals ; researches on the oxy- 

 chlorides of copper, by M. G. Rousseau. Among other bodies of 

 the same type, the author has succeeded in obtaining crystallized 

 atacamite hy his method. — On the combination , of phosphorus 

 pentafluoride with nitrogen tetroxide, by M. Emile Tassel. 

 The body formed, N2O4.PF5 reacts with water in accordance 

 with the equation — 



3(N,04, PF,) -f- i4H20 = 2NO + 4HNO3 + 3H3PO4 + 15HF, 

 thus differing essentially from the corresponding compound 

 containing chlorine. — Heat of formation of uric acid and the 

 alkaline urates, by M. C. Matignon. — Chloralimide and its 

 isomeride ; a reversible isomeric transformation, by MM. Behal 

 and Choay. A mixture of chloralimide (B.P. 169°) and iso- 

 chloralimide (B.P. I03°-I04°) is obtained by the action of 

 heat upon chloralammonia ; the method of separation and puri- 

 fication of each of these bodies is described. Both bodies 

 possess the same molecular weight, Raoult's method with ben- 

 zine for solvent yielding the figures — for chloralimide 430, for 

 isochloralimide 434-435. Each body may be transformed by 

 suitable means, given in detail, into its isomeride. The follow- 

 ing formulae are proposed by the authors as representations of 

 these bodies : — 



NH 

 CCIj-CHf NcH-CCls 



NH 



NH 



CH— CCI3 



Chloralimide. 



NHj 

 CCls-Ci^^CjCCls 

 NHoL yNHj 

 C-CCI3 



Isochloralimide. 



—On an adulteration of linseed oil, by M. A. Aignan. — On the 

 ear gland {Paludina vivipara) and the nephridian gland {Murex 

 brandaris), by M. L. Cuenot.— Researches on multiple buds, 

 by Mr. William Russell. The conclusion is dra\yn that "mul- 

 tiple buds, one springing from another and being vascularljr 



