I2C 



NA TURE 



[December 3, 1891 



by taking into account the conductivity. If, however, we start 

 with von Helmholtz's theory, and introduce a viscous term into 

 the equations of motion of the matter, it will be found possible 

 for the real part of ju^ to be negative, provided the free peiiod of 

 the matter vibrations lies between certain limits. We are thus 

 able to construct a mechanical model of a medium which re- 

 presents the action of metals upon ethereal waves, and which 

 leads to the same formulae for the amplitudes of the reflected 

 waves as those given by Cauchy. — The contacts of systems of 

 circles, by A. Larmor. — On a class of automorphic functions, by 

 Prof. W. Burnside. — Note on the identity 4(x>*-i)/(x i) = 

 Y- ± />ZS by Prof. G. B. Mathews.— On the classification of 

 binodal quartic curves, by H. M. Jeffery, F.R.S. — Researches 

 in the calculus of variations ; discriminating conditions in iso- 

 perimelrical problems, by E. P. Culverwell. — Note on Clifford's 

 paper " On syzygetic relations among the powers of linear 

 quantlcs," by Prof. Cayley, F.R.S. — Note on finding the G 

 points of a given circle with respect to a given triangle of 

 reference, by J. Griffiths. 



Linnean Society, November 19. — Prof. Stewart, President, 

 in the chair. — Mr. S. Jennings exhibited a collection of wild 

 flowers made by him during a recent tour through the Rocky 

 Mountains, California, and Mexico. — Prof. G. B. Howes ex- 

 hibited some dissections of fish crania made by his pupil Mr. 

 R. H. Burne, in which the parts of the skeleton were so 

 displayed that they might be studied in relation to the rest of 

 the head and to the leading cranial nerves. — Mr. E. F. Cooper 

 exhibited specimens of a new variety of Potamogetoti from 

 Loughborough, lately described and figured by Mr. Alfred 

 Fryer {/ourn. Bot., October 1 891).— Mr. A. W. Bennett 

 exhibited and made remarks upon some specimens of Hydro- 

 dictyon utriculatum. Roth. {H. reticulatum, De Toni), and 

 some drawings of anomalous Cypripedium and Disa. — Mr. 

 W. Carruthers, F.R.S., gave a graphic account of a recent 

 visit to Sweden in search of original portraits of Linnaeus, and 

 detailed the results of his inquiries. His remarks were illustrated 

 by an exhibition of engravings and photographs. — A paper was 

 then read by Mr. Thomas Hick, on a new fossil plant from the 

 Lower Coal-measures. An interesting discussion followed, in 

 which Mr. Carruthers, Mr. G. Murray, Prof. F. O. Bower, Prof. 

 Marshall Ward, and others took part. 



Paris. 

 Academy of Sciences, November 23. — M. Duchartre in the 

 -chair. — On some manuscripts with figures of historical interest 

 relating to artillery and mechanical arts towards the end of the 

 Middle Ages, by M. Berthelot. Some manuscripts from libraries 

 at Munich, Venice, and Paris have been examined, and appear 

 to be of interest as marking a stage in the development of 

 applied sciences. A few of the mediasval figures are reproduced : 

 one represents a diver in his costume ; two others show primitive 

 cannon, and one a small-arm used in the fifteenth century. — 

 Preparation and properties of the phosphides of boron, by M. 

 Henri Moissan. By the use of boron phosphoiodide, two boron 

 phosphides may be obtained. The compound PB combines 

 with HNOajHjO with incandescence, and inflames in an 

 atmosphere of chlorine in the cold. The compound P3B5 is 

 ■ much more stable, and is not acted upon in the cold by these two 

 reagents. — On some variations of the glycolytic power of the 

 blood, and on a new method of experimental production of 

 diabetes, MM. R. Lepine and Barral. — M. A. Potier was elected 

 a member of the Academy in the place of the late M. Edmond 

 Becquerel. — Resumi of a verbal report on a note by Prince 

 Tourquistanoff, entitled " Le Calendrier verificateur," by M. 

 Wolf. — Rhutne oi z. verbal report on a note by M. de Cohorne, 

 entitled " Le Regleur solaire," by M. Wolf. — Observations of 

 the total eclipse of the moon of November 15, made at Bordeaux 

 Observatory, by M. G. Rayet. — Remarks «/r^;>^5 of the observa- 

 tion of M. Rayet as to the possibility of photographing the moon 

 during a total eclipse, by M. A. Gautier.— Remarks on M. 

 Rayet's communication, by M. J. Janssen. — Researches on the 

 motions of stars in the line of sight made with the Paris 

 Observatory siderostat, by M. Deslandres. (For the last four 

 communications, see Our Astronomical Column.) — Remark on a 

 communication by M. Markoff relative to linear differential 

 equations, by M. Painleve. — On the flow of liquids in capillary 

 tubes, by M. Albert Colson. The influence of temperature on 

 the rate of flow of viscous liquids is seen from the following com- 

 parison of the times in which 5 c.c. of glycerine passed through 

 •the tube : — 



Temperatures 

 Duration of flow 



21 

 8h. 



100° ... 150° ... 250° ... 265° 

 360^. ... 114s, ... 40-53. ... 33s. 

 The same tube passed 5 c.c. of water at 20" in 34 seconds. The 

 author divides the liquids he has experimented upon into two 

 classes, distinguished by being perfectly and imperfectly mobile. 

 Ethers and aldehydes are representatives of the former class, for 

 they appear to obey Graham's law that the duration of flow, or 

 rather the rate of diffusion, is inversely proportional to the 



square root of the density. The values found for —j— in this 



class of liquids is practically constant. On the other hand, the 

 liquids imparfaitement mobiles, such as alcohols and benzines, 

 furnish irregular values. — Mechanidal determination of the position 

 of the atoms of hydrogen in organic compounds, by M. G. Hin- 

 richs. — Aniline black in dyeing by the dry method, by M. A. 

 Gautier. — On a codeine violet, by M. P. Cazeneuve. — On the 

 distribution of saccharine matters in the different parts of the 

 edible Cipe {Boletus edulis. Bull.), by M. Em. Bourquelot. — On 

 the existence of veins of leucite in a Mont Dore basalt, by M. 

 A. Lacroix. Leucite has not before been recognized in any of 

 the volcanic rocks of the central plateau of France. The author 

 fully describes the petrological characters of the specimens he 

 has discovered, and also their peculiar mode of occurrence. — 

 Earthquakes, submarine eruption, and elevation of land at Pan- 

 tellaria, by M. A. Ricco. Earthquake shocks were felt at 

 Pantellaria on October 14. On October 18, the sea to the west- 

 north-west of the island, at a distance of about 5 kilometres, 

 was seen in violent commotion, and a band of land about i kilo- 

 metre long appeared, from which were ejected masses of heated 

 rock and vapour. On approaching the place of eruption, a 

 large number of dead fishes were found, and it was seen that 

 the band was composed of an immense number of black floaiing 

 masses of rock colliding together with great noise, and vaporiz- 

 ing the water over which they passed. On October 23 the 

 position of the erupted island was determined as lat. 36° 50' N., 

 long, from Paris 9° 33' E. The island was then about 200 metres 

 long by 50 metres wide. The interior of some of the masses of 

 rock- was still hot enough to melt zinc. 



CONTENTS. PAGE 



Field Geology. By Prof. A. H. Green, F.R.S. . . . 97 



The Land of the Lamas 98 



Science and Brewing 100 



A Theory of Gravitation. By A. G. G ico 



Our Book Shelf:— 



" Indischer Ozean : ein Atlas die physikalischen Ver- 



haltnisse, und die Verkehrs-Strassen darstellend" . loi 



Lock: " Mechanics for Beginners " loi 



Hull: "The Physical Geology and Geography of 



Ireland " 102 



Foster: "TheOuse" 102 



Letters to the Editor: — 



A Difficulty in Weismannism. — A. H. Trow; Prof. 



Marcus Hartog 102 



The Mexican Atlatl or Spear- Thrower. — Agnes 



Crane ^ ... 103 



The Chromosphere Line Angstrom 6676 "9. — Rev. A. 



L. Cortie, S.J 103 



Peculiar Eyes. — Jas. Shaw 104 



Zoological Regions. — G. A. Boulenger 104 



Scientific Nomenclature. — H. St. A. Alder .... 104 



" The Darwinian Society." — John S. Flett .... 104 

 Some Notes on the Frankfort International Elec- 

 trical Exhibition. VI. {Illustrated. )....• .105 

 Experiments in Aerodynamics. (Illustrated.) By 



The Right Hon. Lord Rayleigh, F.R.S 108 



Preliminary Notice of a New Branchiate Oligo- 



chaete. By Frank E. Beddard 109 



The Anniversary of the Royal Society no 



Notes 113 



Our Astronomical Column :— 



Motion of Stars in the Line of Sight 117 



The Variation of Latitude 117 



Photography of the Eclipsed Moon 117 



Proposals for a Scheme of Co-operative Observa- 

 tion of the So-called Luminous Clouds 117 



University and Educational Intelligence 118 



Scientific Serials ii8 



Societies and Academies 119 



NO. II 53, VOL. 45] 



