556 



NA TURE 



[April 4, 1901 



becomes comparable with the mean free path of the negatively 

 electrified corpuscles, which on that theory are supposed to carry 

 the electric current, the specific resistance of the substance 

 forming the film will increase, and how it is possible from 

 measurements of this increase to approximate to the mean free 

 path of the corpuscles. It is also shown that the effect of a 

 magnetic field on the resistance decreases with the thickness 

 of the film. 



Paris. 

 Academy of Sciences, March 25.— M. Fouque in ihe 

 chair.— On the Egyptian metals. The presence of platinum 

 among the characters of a hieroglyphic inscription, by M. 

 Berthelot. A metallic box, covered with inscriptions, and 

 dating from about 700 B.C., had a portion of one of its cha- 

 racters made of an alloy of platinum. The specimen was too 

 small for a complete analysis, but from its behaviour towards 

 aqua regia it appeared to be a native platinum, possibly obtained 

 from the alluvial deposits of Nubia or the upper regions of the 

 Nile valley.— On the electrochemical relations of the allotro- 

 pic states of metals, especially of silver, by M. Berthelot. 

 The thermochemical behaviour of the different allotropic modi- 

 fications of silver rendered it probable that a definite electro- 

 motive force could be observed in a cell containing the metal in 

 ■two different states as electrodes. On experiment, this was 

 found to be the case, the direction of the current agreeing with 

 •the thermal sign of the heats of transformation. —On secondary 

 ^radio-activity, by M. Henri Becquerel. The radiation from a 

 •radium salt consists of three parts, the first, very easily absorbed, 

 ;and capable of being deviated by a magnetic field ; the .second, 

 •similar in its nature to the kathode rays ; and the third, very 

 penetrating, but not capable of deviation by a magnet. Experi- 

 ments are described showing the differences in the power of 

 -exciting secondary radiation possessed by these three classes of 

 rays. — The origin of thermal sulphurous waters. Sulphosilicates 

 and oxysulphides derived from natural silicates, by M. Armand 

 "Gautier. An experimental study of the mode of production of 

 -•sulphurous waters. Granite and other igneous rocks, when 

 ••finely powdered andtreated with water at 25o°-300° C. give a 

 .aiquid identical in character with ordinary thermo-sulphurous 

 waters, although of greater concentration. — On some new 

 ■derivatives of dimethylamido-benzoylbenzoic acid, by MM. 

 A. Haller and A. Guyot.— A correction of a preceding com- 

 «munication by M. de Jonquieres. — On a formula of M. Fred- 

 iholm, by M. G. Mittag-Leffler.— M. Sabatier was elected 

 a correspondent for the Section of Chemistry in the place 

 •of M. Haller, named a member of the Academy, and Mr. David- 

 son a correspondent for the Section of Geography and Naviga- 

 tion, in the place of the late M. A. David, — On the general 

 expression of the rational fraction approximating to (i + x)'", 

 by M. H. Pade. — On the formation of nodal lines of sand or 

 dust, by M. C. Maltezos. A suggestion as to the cause of 

 formation of small sandy hillocks on the seashore. — The specific 

 (heat of a gaseous mixture of bodies in chemical equilibrium, by 

 M, A. Ponsot. — The theory of the Wimshurst machine without 

 •sectors, by M. Bordier. — On the measurement of the period of 

 fhe waves used in wireless telegraphy, by M. C. Tissot. The 

 iperiod of the oscillator was measured by the method devised by 

 ^edderson and improved by Decombe. The periods measured 

 were between o*6 X io~® and i 8 x io~®. — The Ritchie telauto- 

 graph, by M. Brauer. This apparatus transmits handwriting 

 ■continuously without the use of clockwork. — On induced radio- 

 activity and gases rendered active by radium, by MM. P. 

 ■ Curie and A. Debierne. It has been shown in a previous com- 

 vniunication that the radio-activity induced by radium salts is 

 effected through the intervening air. It is now found that the 

 ■nature and the pressure of the gas are without effect upon the 

 [phenomenon, but that if a high vacuum is kept up the second 

 body is not affected. On leaving the apparatus for some time, 

 the secondary radio-activity is again observed, and if the gases 

 evolved are again pumped off they, are found to be extremely 

 active in spite of their small mass. Their activity is so great 

 that the glass tube containing them becomes fluorescent, and is 

 visible in the dark. — The direct production of X-rays in air, by 

 M. A. Nodon. Under the simultaneous action of ultra violet 

 rays and an electric field X-rays may be produced without 

 the use of a Crookes' tube. — A method for determining atomic 

 weights founded upon the law of transparency of matter for the 

 X-rays, and the application of this to the atomic weight of 

 indium, by M. L. Benoist. The action of hydrogen upon 

 realgar and the inverse reaction. The influence of pressure and 



temperature, by M. H. Pelabon.— The heat of formation of 

 acetals compared with that of isomeric compounds, by M. Marcel 

 Delepine. — On the acidimetric value of the monosubstituted 

 benzoic acids, by M. G. Massol. — The passage from anisol to 

 anisic acid by five successive oxidations, by M. J. Bougault. — 

 On the law of the auxochromes, by M. P. Lemoult. — ^On 

 naphthylol-naphthyl-oxynaphthylmethane, by M. R. Fosse. — 

 The action of zinc upon the dibromide and diiodide of tetra- 

 methylene, by M. I'abbeJ. Hamonet. On certain causes of varia- 

 tion in the quantity of gluten in wheat, by MM. Leo Vignon and 

 F. Couturier. — Nervous conduction and muscular conduction of 

 electrical stimuli, by M. Aug. Charpentier. — The variation of 

 visual acuteness with lighting and adaptation ; measurement of 

 the migration of the pigment of the retina, by M. Andre 

 Broca. — Curves of thermometric ascent, by M. S. Leduc. — 

 On a parasite observed in the syphilitic, by M. H. Stassano. — 

 On Schistocerca americana, its migration and area of geographical 

 distribution, by M. J. Kiinckel d'Herculais. — The effects of 

 lightning and " gelivure " upon trees, by MM. L. Ravaz and 

 A. Bonnet. By an experimental study of the effects of elec- 

 tricity in motion upon the vine, the conclusion is drawn that 

 the supposed disease of the vine known as "gelivure." and to 

 which a microbial origin has been ascribed, is in reality due to 

 the effects of lightning. — On the age of teschenite, by M. P. 

 Choffat. 



DIARY OF SOCIETIES. 



THURSDAY, April 4. 

 LiNNEAN Society, at 8. — On some British Freshwater Rhizopods and 

 Heliozoa : G. S. West. 



THURSDAY. April ii. 

 Mathematical Society, at 5.30. — Summation of the Series 



2., — ^ ' : D. F. Morley. 



CONTENTS. PAGE 



Space, Atoms, Molecules and the Ether By G. H. B. 533 

 Alleged Hypostomial Eyes in the Trilobiiea. By 



G. B. H 535 



The Relations of the Ostrich-like Birds, By R. L. 536 

 Our Book Shelf:— 



Phipson : " Researches on the Past and Present 



History of the Earth's Atmosphere " . . . 537 



Seward : " Catalogue of the Mesozoic Plants in the 

 Department of Geology, British Museum (Natural 

 History). The Jurassic Flora. I. The Yorkshire 



Coast" 537 



Parr : ' ' Practical Electrical Testing in Physics and 



Electrical Engineering " 538 



Letters to the Editor : — 



Audibility of the Sound of Firing on February i. 

 {With Diagrams.)— Kohl. B. Hay ward, F.R.S. 538 



The New Star in Perseus, —C. Easton 540 



Nova Persei 540 



The Beer Poisoning Epidemic 541 



Musical Arcs .... 542 



Little's Expedition to Omi and the Tibetan Border. 



{Illustrated.) 543 



Prof. Josef von Fodor. By W. H. C 544 



Notes 544 



Our Astronomical Column : — 



Rulherfurd Measures of Pieiades 54S 



Catalogue of Southern Variable Stars 548 



On a Solar Calorimeter depending on the Rate of 

 Generation of Steam. {Illustrated.) By J, Y. 



Buchanan, F.R.S 5^8 



The Mining Statistics of the World. By Bennett 



H. Brough 551 



The Mineral Constituents of Dust and Soot from 

 various Sources. By Prof. W. N. Hartley, F.R.S., 



and Hugh Ramage 552 



Studies in Visual Sensation. By Prof. C. Lloyd 



Morgan, F.R.S 552 



University and Educational Intelligence .... 553 



Societies and Academies 554 



Diary of Societies 556 



NO. 1640, VOL. 63] 



