132 



NATURE 



\Pec. 7, 1876 



Cambridge 



Philosophical Society, November 6, 1876. — Mr. J. W. L. 

 Glaisher made a communication to the Society on a formula of 

 Cauchy's for the evaluation of a class of definite integrals.— Prof. 

 Hughes exhibited three series of specimens in illustration of the 

 mode of (i) formation, (2) weathering, and (3) fracture of flint, 

 the first two being selected chiefly with a view to the last. He 

 produced proofs that the supposed faulted and re-cemented flints 

 were generally only flint that had irregularly replaced jointed 

 chalk, the formation of the flint being arrested by the joints. In 

 the case of the banded flints he exhibited and distinguished two 

 j^inds — one in which infiltration had taken place all round the 

 outside, often a good test of the drift origin of certain fragments ; 

 and the other in which a difference of texture, due generally to 

 some included organism, had determined and limited the areas 

 over which infiltration had produced bands of colour. He 

 pointed out that these differently coloured included portions, 

 whether banded or not, affected the fracture, as they also 

 depended upon the texture of the flint, but that the bands them- 

 selves had little or no influence upon the fracture. He then drew 

 attention to a series of specimens which showed that when flint 

 or other material of a similar texture was struck by any object 

 such as a round-headed hammer, so that the blow was sym- 

 metrically distributed over a small area, a bruise was produced 

 which on weathering flaked off all round a small cone having an 

 angle at its apex of about 110°, and that when the whole had 

 flaked away a smooth basin was left. But if, and only if, the 

 blow was sufficiently intense to break the flint up, this cone was 

 found to truncate a larger cone whose apex had an angle of about 

 30°. He pointed out that modifications of this double cone 

 structure explained the "rings" and "bulb of percussion" 

 which were appealed to as evidence of the direction of blows on 

 which arguments were founded as to the origin of soTie stone 

 implements. 



Paris 



Academy of Sciences, November 27. — Vice-Admiral Paris 

 m the chair.— The following papers were read : — On the crystals 

 of magnetic oxide of iron formed during the roasting of a spathic 

 ore, by M. Boussingault. — On various works of hydraulics, exe- 

 cuted by the ancients in the environs of Rome, by P. Secchi. 

 He notices, shortly, an inverted siphon aqueduct at Alatri, a 

 complete system ot drainage there, mode of supplying purified 

 rain-water to the town of Segni, filtration through porous soils, 

 mode of cooling the aqua tefula. and of removing carbonate of 

 lime from water. P. Secchi has found the spring w^hich fur- 

 nished the aqua ieptila ; its temperature is 17° to 18° C. in winter, 

 and it cannot have been over 18° when the ancients_ used it ; 

 this shows the extreme slowness of cooling in the interior of the 

 globe.— On a remarkable fall of hail observed at Grotta Ferrata, 

 by P. Secchi. The hail cloud appeared like an immense ball of 

 cotton or wool, and it advanced with a whirling movement from 

 south-east to north-west. Tlie first rain drops were very large, 

 at least i cubic centimetre. The hailstones which followed 

 were formed of groups of crystals like those of quartz gathered 

 round an irregular mass of ice. These groups weighed 40 to 60 

 grammes; certain blocks at Marino, 300 grammes. Round 

 grains, with concentric layers, were very few. P. Secchi thinks 

 electricity not the cause but the effect of hail. — On the composi- 

 tion of gun-cotton, by Prof. Abel. This refers to a note by 

 MM. Champion and Pellet.— On a new electric repulsion and 

 its application to the theory of comets, by MM. Reitlinger and 

 Urbanitzky. Operating with air, oxygen, hydrogen, nitrogen, 

 &c., in Geissler tubes, they got, under pressures of 2 to 8 mm., 

 the usual attraction in the luminous column when the finger, or 

 any conductor was brought near ; but, pursuing the rarefaction 

 further, a repulsion. Using a tuba like an electric egg, the 

 nebulous light was like the tail of a comet, and the repulsion was 

 very strong, and manifest at a great distance,— On the portative 

 force of horse-shoe magnets ; extract from memoir by M. van 

 der Willigen. To saturate his magnets he places them vertically 

 with thtir poles on those of a Ruhmkorff coil, the circuit of 

 which he opens and closes several times ; the magnetism in the 

 magnets then reaches its maximum, even supersaturation. After 

 the last opening, he slides the magnet carefully towards the edges 

 of the polar planes of the electro-magnets. Then he puts the 

 well-cleaned support before the magnet, inclining the latter 

 slowly. Immediately the support has joined the magiiet, the 

 latter can be removed without effort ; its portative force is then 

 nearly a third greater tha.n the permanent portative force of M. 



von Wetteren's best magnets. This state ef supersaturation he 

 makes the starting-point of his researches. — Researches on the 

 vitality of the eggs of phylloxera (second paper), by M. Balbiani. 

 He examines the action of alkaline sulphocarbonates, sulphide ot 

 carbon, and empyreumatic products. — Treatment of phylloxerised 

 vines, by M. Boiteau. — On a question of ballistics, by M. Astier. 

 — On the determination of groups formed of a finite number of 

 linear substitutions, by M. Jordan. — On the application of 

 methods of mathematical physics to the study of bodies ter- 

 minated by cyclides, by M. Darboux. — Construction for a point 

 of the curve of intersection of two surfaces with the centre of the 

 osculating sphere of this curve, by M. Mannheim. — Explanation 

 of actions at a distance ; gravitation, electric actions, by M. 

 Picart. He explains all phenomena by matter in motion. — 

 Crystals of gallium, by M. Lecoq de Boisbaudran. These 

 are octahedra truncated at the base ; the angles indi- 

 cate a clino-rhombic form. — Note on the determination 

 of sugars by means of titrated liquors, by M. Perrot. — 

 Second note on testing for fuchsine in wines, by M. Ford->s. 

 — Researches on the real origin of nerves of general sensi- 

 bility in the medulla oblongata and the spinal chord, by M. 

 Pierret. — On the physiological action of temperatures below zero, 

 on silk-worm grains, by M. Duclaux. To the limit, at least, 

 of — 10", the effects produced on the grain by lowering the 

 temperature are comparable in their nature, and differ only in 

 their intensity ; this' intensity does not increase or decrease 

 re ^ularly with the temperature, but presents a maximum for a cer- 

 tain point of the thermometric scale. This physiological zero of 

 the grain is probably a little above the orimary zero. — On the 

 structure of the optical system in crustaceans, by M. Chatin. — 

 Synoptic table showing the distribution of fossil molluscs in the 

 Tertiary layers of the Pari^ valley, by M. Meunier. — On a crystal- 

 lised silicate of baryta obtained artificially, by M. Pisani. — On 

 the study of the barometer, by M. Wickenrieimer. i. The mean 

 of barometric observations, made at any hour for all the days of 

 the month, gives a constant number, whatever the hour. 2. The 

 barometric height passes two maxima and two minima daily. 3. 

 The annual barometric mean is constant for all hours of the day. 

 — Observation of descending trombss, made at the Cape of 

 Antibes, November 21, 1876, by M Ferreri. 



CONTENTS Paqs 



The Yorkshire Lias ^'3 



Our Book Shelf : — 



Max. von Hantken's " Die Fauna der Clavulina Szab6l Schichten " 115 

 Atkins's "Elements of Algebra for Middle-Class Schools and 



Training Colleges " ^'S 



Lbttkrs to the Editor : — 



Carl Jelinek.— Dr. Ch. DE LiTTROW ; "S 



Ancient Solar Eclipses— Sir G. B. Airy, F.R.S nS 



Negretti's Reversible Thermometer and the Arctic Expedition.— 



SirG.S. Narks "5 



The Arctic Expedition.— Wordsworth DoNNiSTHORPE . ... 116 

 The Age of the Rocks of Charnwood Forest.— Prof. Edward 



Hull, F.R.S "6 



"Towering" of Grouse, Partridges, &c.— George J. Romanes . ii5 



Squirrels.— Henry H. Higgins i'? 



Mr. Harris's Challenge to Mathematicians —The Writer of 



THE Article "7 



A Zoological Station on THE North Sea (;^«VA///«j/m2!/(?«) . 117 



Sensitive Flame Apparatus for Ordinary Gas Pressure, and 

 some Observations thereon. By-R. H. Ridout {IVitA /llus- 



trations) "9 



On the Conditions of the Antarctic, II. By Sir C. Wyville 



Thomson, F.R.S. {IVith Ilhistrations) ..;...-... 120 



Nordenskjold's Expedition to the Jenissei ' 123 



Our Astronomical Column : — 



Telescopic Meteors • • 1^5 



The Comet of the Bayeux Tapestry i25 



Meteorological Notes : — 



Recent Storms i^o 



Meteorological O'oservatory in Monte Cavo 126 



Biological Notes : — 



The Primary Elements of the Skull . 127 



The Anatomy of the Gorilla ^27 



The Windpipe in Manucodia 127 



Notes • '-7 



Scirntific Serials ^3° 



Societies an» Academies 130 



