566 



NA TURE 



October i, 1908 



of specialists for the particular branches of industry which 

 prevail in the district ; but at the foundation of these in- 

 dustries there is one fundamental factor which affects each 

 and all of them — they all depend ultimately on the com- 

 bustion of coal for the production of light, heat, and 

 power. Since the special laboratories were opened in 

 connection with the Young chair of chemistry, Prof. 

 Thomas Gray has carried out systematic instruction on 

 the methods used for the scientific control of the combus- 

 tion of coal and the economical utilisation of heat in 

 factories. Not only are the regular students of chemistry, 

 metallurgy, and engineering instructed in these methods as 

 a necessary part of their curriculum, but similar instruc- 

 tion has been sought for and obtained by the members of 

 the staff of a number of leading' industrial concerns in the 

 district. 



SOCIETES AND ACADEMIES. 

 London. 



Royal Society, June 4. — "The Viscosity of Ice." 

 By R. M. Deelsy. Communicated bv Henry Woodward, 

 FiR.S. 



The rate of motion of a number of glaciers has been 

 determined by Tyndall. From his figures and estimates of 

 their thickness and slope it is possible to calculate with 

 some degree of accuracy the viscosity of several glaciers. 

 Stated in dynes per square centimetre X 10'", the results 

 are roughly as follow : — the Mer de Glace, 27 : Morteratsch, 

 143 ; Lower Grindelwald, 3 ; and Great .^letsch, 126. It 

 seems probable that these differences arise mainly from 

 differences in the actual viscosity of the glacier ice due to 

 its varying granular structure. It is shown that the 

 viscous flow of a glacier exercises a drag on the floor upon 

 which it rests amounting in the case of the Great Aletsch 

 to about 2A tons per square foot, and that owing to the 

 ability of the ice to transmit thrust, this force may be 

 greatly exceeded at points where much resistance to motion 

 is caused by inequalities in the floor upon which the ice 

 rests. 



McConnel made a number of experiments on the shear- 

 ing motion which can be produced in ice crystals in direc- 

 tions at right angles to the optic axis. It is shown that 

 this shear obeys the laws of viscous motion, and that the 

 viscosity may be expressed by the following equation : — 



■ogio/' = o-3oH-iS3'-o-oo23i(=, 



where ju is the viscositv in dynes per square centimetre X 

 io'°, and ( is the temperature below zero C. (considered 

 fHjsitive). McConnel showed that when the load was taken 

 off a bar of ice which had been yielding viscously, there 

 was a slow partial recovery of the original form. Experi- 

 ments with highly brittle pitch also showed that when the 

 load was taken off a weighted bar there was an immediate 

 elastic recovery, and also an additional slow recovery. 

 This feature has also been described by Trouton. 



The viscosity of ice at right angles to the optic axis is 

 about 6250 times less than that of a glacier ; the optic 

 axis of glacier grains being at all angles, they lock each 

 other. The motion of a glacier is due in a large measure 

 to changes in the sizes and shapes of the glacier grains 

 due to their growth and decay. 



Paris. 

 Academy of Sciences, September 21. — M. Bnurhard in 

 the chair. — The determination of the triple orthogonal 

 systems which comprise a family of cvclids, and, more 

 generally, a family of surfaces with lines of curvature 

 plane in the two, systems : Gaston Darboux. — The use of 

 tartar emetic in the treatment of trypanosomiasis : A. 

 Laveran. Guinea-pigs infected with T. evansi, T. 

 gambiciise, and the trypanosome of Togo, were treated 

 with hypodermic injections of a solution of sodium anti- 

 monyl tartrate in 2 per cent, solution. The results were 

 generally favourable, especially when the antimony salt 

 was used in conjunction with atoxyl. — The impossibility 

 of demonstrating the existence of an appreciable dispersion 

 of light in interstellar space by the Nordmann-Tikhoff 

 method : Pierre Lebedew. The ratio of the dispersion 



NO. 2031, VOL. 7SI 



values found by Xordmann and by Tikhoff is 30 : i, and 

 the author concludes that a method of measurement which 

 gives such different values for the same physical constant 

 must be false in principle. — The spectra of the large planets 

 photographed in 1907 at the Flagstaff Observatory : 

 Percivai Lowell. The principal lines and bands observed 

 for Jupiter, Saturn, Uranus, and Neptune are tabulated. 

 The presence of water vapour in the atmospheres of Jupiter 

 and Saturn is proved, and also free hydrogen in Uranus 

 and Neptune. — Reciprocal differences 1 E. Norlund. — A 

 lecture experiment concerning the rotation of the earth : 

 Louis MaiMard. — .-\ particular form to which the differ- 

 ential equations of the trajectories of electrified corpuscles 

 in a magnetic field can be reduced : C. Stormer. — The 

 origin of the Brownian motion : Jean Perrin. Further 

 experiments are described confirming the hypothesis that 

 molecular agitation is the cause of the movement. — The 

 thermoelectricity of cobalt : H. Pecheux. .A study of a 

 copper-cobalt thermocouple shows that molecular trans- 

 formations occur in cobalt at 280° C. and 550° C. — 

 Oleuropine, a new principle of glucoside nature extracted 

 from the olive (Olca eiiropca) : Em. Bourquelot and 

 J. Vintilesco. — The function of the nervous system in the 

 changes of colour in the frog : E. Soliaud. — The supposed 

 action of tobacco in producing abortion : R. Robinson. 

 Evidence is adduced negativing this supposed action. — The 

 cause of magnetic storms : K. Btrkeland. 



CONTENTS. PAGh 



Mathematical Aspects of Electricity and 



Magnetism. By Dr. C. Chree, F.R.S 537 



Petrels. By O. V. A 53S 



Our Book Shelf:— 



Meyer : " Das Weltgebiiude, Eine gemeinversland- 



liche, Himmelskunde " 53^ 



" Practical Coal Mining " 539 



Letters to the Editor : — 



Photographs of Comet r 1908 at the Royal Observatory, 

 Greenwich.— Sir W. H. M. Christie, K.C.B., 



F.R.S 539 



Library Cooperation in Regard to Scientific Serials. — 



Dr. Thos. Muir, C.M.G., F.R.S 539 



Research Woik on Natural Indigo. — T. R. Filgalt ; 



Prof. R. Meldola, F.R.S. ;"C. Bergtheil , 540 



An Alleged Excretion of Toxic Substances by Plant 

 Roots. — Howard S. Reed . 540 



Surveying for Archaeologists. IV. [lllustyaled.) 



By Sir Norman Lockyer, K.C.B,, F.R.S 542 



The Horned Dinosaurs. {Illuslratcd.) By R. L. . . 544 



Notes 545 



Our Astronomical Column : — 



Comet Morehouse 549 



Large Group of Sun-spots 55° 



The Orbit of (,' Cancri C 550 



Seaich-ephemeris for Comet Tempel^-Swift 55° 



The Manora Observatory 55° 



A Nebulous Field in Taurus 55° 



The Isothermal Layer of the Atmosphere 550 



Third International Congress for the History of 



Religions 552 



The British Association : — 



Section I. — Physiology. — Opening Address by J. S. 

 Haldane, M.D., F.R.S., Fellow of New 

 College and Reader in Physiology in the 

 University of Oxford, President of the 



Section 553 



Section K. — Bo'any. (Willi /Jm^vwwj.)— Opening 

 Address by F. F. Blackman, M.A., U.Sc, 



K.K.S., President of the section 556 



The Scientific Study of Plague. By L. Noon . . . 564 



University and Educational Inielli^enct 565 



Societies and Academies 566 



