33^ 



NATURE 



[August 5, 1897 



Paris, 

 Academy of Sciences, July 26. — M. A. Chatin in the 

 chair. — The gnomon of the Observatory and the old values of 

 the toise : recovery of the Picard toise, by M. C. Wolf. — 

 Establishment pf a uniform state in a pipe of circular 

 section, by M. J. Boussinesq. — On the composition of 

 drainage water, by M. P. P. Deherain. The formation of 

 nitrate from the nitrogenous stock in the soil, by the action of 

 organisms, is greatly accelerated by moisture ; hence the ad- 

 vantage of irrigation where possible. — Researches on the state 

 in which elements other than carbon occur in cast iron and in 

 steel, by M. H. Ad. Carnot and Goutal. A continuation of a 

 previous paper. Manganese combines as far as possible with 

 the sulphur and silicon, any excess being simply dissolved in the 

 iron. No compound of copper or nickel appears to be formed. 

 Chromium is present in combination with both carbon and iron. 

 Tungsten forms a definite compound, FcgW ; molybdenum, 

 FcsMoj. — On the explanation of an experimental result at- 

 tributed to a magnetic deviation of the X-rays, by Sir G. G. 

 Stokes. Some remarks on an observation of M. G. de Metz. 

 Thj^ X-rays, as a mode of vibration of the ether, are not 

 susceptible of deviation by a magnet ; the kathode rays, on the 

 other hand, consisting of a stream of electrified particles, are 

 affected by the magnet. The kathode rays, moreover, are 

 ■stopped by an air layer, and will only be able to affect a fluor- 

 -escent screen as the vacuum is increased. The experiments of 

 M. de Metz find a very simple explanation in these facts. — On 

 ihe toxicity of the perspiration of a healthy man, by M. L. 

 Arloing. Experimental results are given clearly showing the 

 toxic action of normal perspiration. — Remarks on the preceding 

 -paper, by M. Berthelot. — On phthalic green, its preparation 

 and constitution, by MM. A. Haller and A. Guyot. The forma- 

 tion of this colouring matter by the action of zinc chloride upon 

 dimethylaniline and phthalyl chloride, is shown to depend upon 

 -the presence of phthalyl tetrachloride {CgHg.CCls.COCl) in the 

 ■latter. Starting with this tetrachloride instead of the dichloride, 

 yields of from 60 to 95 per cent, of the colouring matter 

 are obtained, the constitution of which is different from 

 that assigned to it by its discoverer (Otto Fischer).— On 

 a generalisation of, the problem of representation in three 

 dimensions, by M. Emile Cotton. — The natural rotatory dis- 

 persion of quartz in the infra-red, by M. R. Dongier. The 

 experimental method used gives results of a higher order of 

 accuracy than any previously recorded ; and no formula for the 

 rotatory dispersion of quartz deduced from theoretical consider- 

 ations will include both the visible spectrum and these results 

 for the infra-red.— On the transformation of the X-rays by 

 metals, by M. G. Sagnac. Different metals exert a selective 

 absorption upon the X-rays. At the same time, the surface 

 layer of the metal emits new rays which are transmitted through 

 .mica, aluminium, and black paper with much greater difficulty 

 than the X-rays themselves. — On the veiled appearance of photo- 

 graphs taken with the X-rays, by M. P. Villard. The effect 

 ■produced is not due to rays which have traversed all obstacles, 

 since it is obtained under really opaque substances. The 

 fluorescence of the .surrounding air appears to be the source of 

 the second image, and great difficulties are encountered for this 

 reason in the radiography of a thorax. —Action of the X-rays 

 upon the temperature of animals, by M. L. Lecercle. The 

 cutaneous and rectal temperatures are both modified in the 

 same direction by the X-rays, the temperature bemg at 

 first lowered, but afterwards rising.— Researches on the 

 nickel-steels. Expansions at high temperatures, the elec- 

 trical resistance, by M. C. E. Guillaume. The results ob- 

 itained for the variation of the electrical resistance with tem- 

 perature show that this cannot be considered as a simple conse- 

 .quence of the expansion.— On the spectrum of the lines of 

 carbon in fused salts, by M. A. de Gramont.— Relation between 

 -the polymerisation of liquid substances and their dissociating 

 jpower upon electrolytes, by M. Paul Dutoit and Miss E. Aston. 

 'An experimental study of the electrical conductivities of some 

 salts dissolved in propionitrile, acetone, methyl-ethyl-acetone, 

 methyl-propyl-acetone, and nitroethane, all of which may be 

 considered as polymerisedliquids.— On anewgroupof amidmes, 

 by M. Fernand Muttelet.— On a method of estimatmg acety- 

 lene, generally applicable to hydrocarbons of the formula 

 R.C;CH, by M. Chavastelon. By the action of acetylenic 

 hydrocarbons upon an aqueous or alcoholic solution of silver 

 nitrate, two molecules of nitric acid are set free for each mole- 

 cule of acetylene absorbed. The estimation of such hydro- 



NO 1449. VOL. 56] 



carbons is thus reduced to a simple titration of an acid. — On 

 the estimation of lime, aluminium, and iron in mineral phos- 

 phates, by M. L. Lindet. — On the absorption of oxygen in the 

 decolorisation of wine, by M. J. Laborde. — Influences exercised 

 by the pathological state of parents upon their descendants, by 

 M. A. Charrin. — Bacteriological study of ambergris, by M. H. 

 Beauregard. — The persistence of the activity of rennet at low or 

 high temperatures, by MM. L Camus and E. Gley. — On a new 

 form of the buccal apparatus of the Hymenoptera, by M. J. 

 Perez. — On a new My.xosphoridia of the family of Glugeidea, by 

 M. Louis Leger. — On the carboniferous ground in the neigh- 

 bourhood of Macon, by M. A. Vaffier. — On the marcasite of 

 Pontpean, and on the regular grouping of marcasite, pyrites, and 

 galena, constituting pseudomorphs of pyrrhotine, by M. A. 

 Lacroix. — On some new applications of the oscillating current 

 in electric therapeutics, by M. le Dr. G. Apostoli. 



PAMPHLETS AND SERIALS RECEIVED. 



Pamphlets.— Royal Gardens, Kew : Hand-List of Tender Monocotyle- 

 dons, excluding Orchideae, cultivated in the Royal Gardens, Kew, 1897 

 (London).— The Mammoth Cave of Kentucky : Dr. Hovey Call (Louisville, 

 Morton).— The Birds of Colorado: W. W. Cooke (Fort Collins, Col.).— 

 Report of the International Meteorological Conference, Paris, i8q6(Eyre). 



Serials.— Journal of the Royal Statistical Society, June (Stanford) — 

 Journal of the Chemical Society, July (Gurney).— Morphologisches Jahr. 

 buch, 25 Band, 2 Heft (Leipzig, Engelmann).— Bulletin of the Natural 

 History Society of New Brunswick, Vol. xv. (St. John).— L'Anthropologie, 

 May and June (Paris, Masson).— Notes from the Leyden Museum, January 

 and April (Leiden).— Natural Science, August (Dent).— Zeitschrift fUr 

 Physikalische Chemie, xxiii. Band, 3 Heft (Leipzig, Engelmann). 



CONTENTS. PAGE 



Ore Deposits. By C. L. N. F 313 



The Resistance of the Air 3^4 



Teaching the Teachers 31S 



Our Book Shelf:— 



" Abhandlungen zur Physiologic derGesichtsempfind- 



ungen" S'S 



Vallier :" Cuirasses et Projectiles de Marine " . . . 315 

 Miron : " Les Huiles mine rales ; Petrole, Schiste, 



Lignite" 3^5 



Detmer : " Botanische Wanderungen in Brasilien " . 315 

 Letters to the Editor:— 



Rontgen Ray Theory.— A. Vosmaer and F. L. 



Ortt 316 



Some Further Experiments on the X-Rays. — T. C. 



Porter 3^6 



Primitive Methods of Drilling.— Franz Calice . . . 317 



Meteor of July 29.— J. V. Ramsden 3^7 



The Approaching Total Eclipse of the Sun. III. 



{Illustrated.) By J. Norman Lockyer, C.B., F.R.S. 318 

 On Lunar and Solar Periodicities of Earthquakes. 



By Prof. Arthur Schuster, F.R.S 321 



Notes 321 



Our Astronomical Column : — 



The Periodic Comet D' Arrest 324 



Natal Observatory Report 324 



Chronometers 324 



New Determination of Precessional Motion 324 



Diamonds. {Illustrated.) By Sir William Crookes, 



F.R.S 325 



The Institution of Mechanical Engineers 331 



A Troublesome Aquatic Plant 332 



Theory and Practice. By Prof. T. Clifford AUbutt, 



F.R.S 332 



University and Educational Intelligence 334 



Scientific Serials 335 



Societies and Academies 335 



Pamphlets and Serials Received 33^ 



