February 15, 1900] 



NATURE 



^8; 



Callovian ; (3) Possibly a pre-Jurassic part of the Duruma 

 Sandstone ; (2) Magarini sandstones ; PTriassic ; (l) Sabaki 

 shales ; Upper Carboniferous. 



Manchester. 

 Literary and Philosophical Society, February 6.— Prof. 

 Horace Lamb, F.R.S., President, in the chair.— On the con- 

 ditions of propagation of a solitary wave, by R. F. Gwyther. 

 In order to obtain mathematical formulae capable of expressing 

 in a few terms the equality of surface pressure over the long 

 stretches of the solitary wave, the wave is regarded as being 

 mainly supported by the pressure on the outskirts, any defect 

 in the equality of pressure over the crest being looked on, under 

 certain conditions, as overcome by a slight readjustment of the 



particles. Takingin x + »>aterm of the form tan A;;/^*^"^"^, it is 



c 

 shown that the results agree closely with the experimental re- 

 sults of Scott Russell. — On the motion of the particles in certain 

 cases of steady fluid motion, by R. F. Gwyther. It is shown 

 that the solution of the Lagrangian equations takes the form 

 \ +ty=J{u + td), where u is to be determined in terms of a, b, 

 and /, by a quadrature.— On internal migration in England and 

 Wales, 1881-91, by Prof. A. W. Flux. An account is given of 

 the results of an examination of the net inward and outward 

 movement in each registration district of England and Wales 

 in the interval between the censuses of 1881 and 1891. The 

 movement of the two sexes separately was taken, as differences 

 in intensity and direction for males and females were not in- 

 frequent. Of the 54 registration counties (the Ridings of York- 

 shire being separately considered), 40 showed net efflux for both 

 sexes, and 7 others for one of the two sexes ; of the 632 dis- 

 tricts 124 only showed net influx of population taking the sexes 

 together, this figure being reduced to 119 for males and raised 

 to 136 for females. The net movements within the various 

 counties involved a transference of about 304,000 males and 

 350,000 females from one district to another. Movement from 

 a district in one county to one in another county involved a 

 transference of about 172,000 males and 230,000 females, whilst 

 some 418,000 males and 201,000 females left the country. The 

 previously observed greater migratory tendency of the female 

 seems at any rate partly due to the fact that when migration is 

 tested by records of birth-places, the excess of migratory males 

 are not included, owing to their removal beyond the limits of 

 the kingdom. Measuring intensity of movement by the propor- 

 tion of net migration to mean population, the absorption is 

 most marked in London suburbs, and in those of some pro- 

 vincial towns in only a slightly less degree, and especially is 

 marked inconveniently situated watering-places at the seaside, 

 Bournemouth heading the list. The absorption into growing 

 industrial towns is less strongly shown than might have been 

 anticipated. These movements indicate some amelioration of 

 the evils of life in crowded cities. The districts from which 

 eftlux has been strongest are found in the south-west, in Wales, 

 on ihe Scotch border, and in north-east Yorkshire and Lincoln- 

 shire. A cartogram illustrating the movements was exhibited. 



Dublin. 

 Royal Irish Academy, January 22. — Dr Benjamin 

 Williamson, F.R.S., Vice-President, in the chair— Rev. W. R. 

 Westropp Roberts, F.T.C.D., read a paper " On the Reduction 



of the Integral / -*i^lli_ to a number of other Integrals of 

 J ^^(z) v//(2) 



the form / ^ _ ~, where <p(z) and y^,{z) are rational and in- 



J{z-n)^l/[z) 

 tegral functions of z and f(z), a polynomial of the degree 2m." 

 The writer showed, in the first instance, the dependence of the 

 above integral on 2/« - i Integrals i^, ij, . . . i.^,„ _ i,and others 

 of the form L{2, «), having previously adopted the notation 



T — /" z^dz J , r dz , . 



^' — / —7 =— .L(3, « r:^ / ^^-, r being an integer. These 



J s/A^) J{z-n)sJAz) 



2m - I Integrals Iq, ii, . . . ig-mi are ultimately shown to de- 

 pend on Integrals of the form L(2, «), in which « is specially 

 related to the roots of y^s) = o The result finally arrived at is 

 that there is but one class of elementary Integrals, as the general 

 Integral discussed in the paper can, in all cases, be made to 

 dejiend on a number of others of the form L(2, ;/) — Prof. J. P. 

 O'Reilly read a paper on the Epidiorites of Killiney Park, 

 Dublin county. He called attention to the description of the 



NO. I581, VOL. 61] 



locality given in the Memoir of the Geological Survey 0/ 

 Ireland descriptive of the district, and pointed out that no 

 mention is made therein of these i>Dcks, although reference is 

 made to those met with in Howth and other parts of the dis- 

 trict. Considering the fine exposure shown at Killiney Park, 

 and the accessibility of the point, he thought it desirable to 

 make a map of the point where the rocks crop out, showing 

 their connection with the micaschists ; which map was .sub- 

 mitted with the paper. He also had analyses of the Epidiorite 

 and of the enclosing micaschists made, and gave them in the 

 paper. He called attention to the occurrence of similar mica; 

 schists at Bray Head, and suggested the possibility that th^ 

 Killiney Park rocks may be the same beds as those of Bray 

 Head, but in a much more advanced stage of metamorphosis. 



Paris. 

 Academy of Sciences, February 5.— M. Maurice Levy 

 in the chair.— Calculation of the orbit of a comet of which the 

 geocentric movement is considerable, by MM. O. Callandreau 

 and G. Fayet. Although the calculations of the orbits of the 

 minor planets are sufliciently exact to enable the asteroid to be 

 easily traced from day to day, considerable differences arise 

 between the actual and calculated positions of some of the, 

 newer comets. A simplification of Olbers' method is suggested^ 

 which, with the aid of the auxiliary table suggested by M., 

 Radau, gives very easily a good approximation.— The locali- 

 sation, elimination and origin of arsenic in animals, by M. 

 Armand Gautier. The amounts of arsenic normally present in 

 100 grams of the fresh organ are, for the thyroid gland, 075 

 mgr. ; the mammary gland, 0-13 mgr. ; for the brain, trace or 

 nothing ; thymus gland, a distinct trace, not estimated ; for 

 skin, milk, and bone, decreasing traces. The liver, kidney, 

 spleen, muscles, testicles, pituitary gland, pancreas, mucous 

 membranes, cellular ti.ssue, salivary glands, subrenal capsules, 

 ovaries, urine and faces contain no trace of arsenic. With the 

 view of ascertaining the possible sources of arsenic in the food 

 supply, various food stuffs were carefully examined for this 

 metalloid : bread, meat and fish contained absolutely none, eggs 

 gave a very doubtful trace. The author discusses the medico- 

 legal aspect of the question.— Attempt at a mechanical theory 

 of mountain formation. Progressive displacement of the terres- 

 trial axis, by M. Marcel Bertrand. The view is put forward 

 that the solid crust to the earth yields slowly to the pressures 

 acting upon it, exactly as a liquid would do, except that the 

 duration of the motion, instantaneous for a fluid, is exceedingly 

 slow in the case of a solid.— On a disease of the grape-vines of 

 the Caucasus, by MM. Prillieux and Delacroix. Previous 

 workers on the outbreak of vine disease in the Caucasus, in 1896, 

 have ascribed the results as due to the fungus of black rot 

 (Guignardia Bidwelli), but closer examination has shown 

 that it is another species of Giiignardia, which corre- 

 sponds to Phoma renifor/nis, which is the cause of the 

 Tiflis disease, to which the authors attribute the name of 

 Gtiignardia femyor»/2S. — Observations of the comet 1899 IV. 

 (Temple, 1873 ii.) made with the large equatorial at the 

 Observatory of Bordeaux, by MM. G. Rayet, Feraud and 

 Esclangon.— On the second voyage of the Princess Alice IT., by 

 S. A. S. Prince Albert of Monaco. — Study of the variation of 

 latitude at the Observatory of Teramo, Italy, by M. Jean Boc- 

 cardi. The measurements were carried out by the method of 

 Horrebow-Talcott, with an instrument of Troughton and Simms 

 of 75 mm. aperture. For four different pairs of stars the varia- 

 tions of latitude found were i" 00, o"84, o"67, and o"98 re- 

 spectively.— On a class of transformations, by M. J. Clairin. — 

 On the determination of all the algebraic surfaces of double 

 circular generation, by M. Eugene Cosserat.— On anharmonic 

 algebraic equations, by M. Antonne.— On groups of isomor- 

 phisms, by M. G. A. Miller. — On vectorial masses of discon- 

 tinuity, by M. Andre Broca.— The X-rays and discharge : gene- 

 ralisation of the notion of kathode rays, by M. G. Sagnac. A 

 sealed note deposited July 18, 1898.— Contribution to the study 

 of stratifications, by M. H. Pellat. Some experiments designed 

 with a view to test the hypothesis that the stratifications produced 

 in a Geissler tube are due to the interference of direct and re- 

 flected electric waves. The result was to negative this hypo- 

 thesis, there being apparently neither a reflected electric wave 

 nor electric oscillations. — On the metallic crystallisation by 

 electrical transport of certain metals in distilled water, by M. 

 Thomas Tommasina. — On the surface tension of some organic 

 liquids, by MM. Paul Dutoit and Louis Friderich. Measure- 



