456 



NA TURE 



\ April 9, ii)74 



these acids into the interior of the iron, does not account for a 

 number of phenomena that have been observed so often and so 

 carefully as to leave no doubt of their invariable recurrence if 

 the conditions of experiment be only properly observed. It 

 seems to the author that the only satisfactory way of explaining 

 all the phenomena is to suppose that when a piece of iron is 

 immersed in acid two actions go on, viz. : an absorption of the 

 nascent hydrogen into the interior of the iron, which hydrogen 

 may subsequently be given off by gentle heat or immersion in a 

 liquid, &c. Secondly, an absorption of the acid itself, possibly 

 in a very concentrated form, by the insterstices between the fibres 

 or crystals of the metal. It will however be said, the acid must 

 act on the walls of the cavity and form a salt of iron with libera- 

 tion of hydrogen. This may go on to a small extent, but in 

 opposition to this view we may bring the experiments of Prof. 

 Bequerel on solutions separated by a cracked tube (Coviptes 

 Heiidiis, Ixxvi. ), where he shows that no precipitate is formed on 

 placing a cracked tube filled with nitrate of lead in a solution of 

 potassium sulphate within the crack, thus making it probable 

 that chemical interchanges do not take place in very minute 

 spaces. By this theory we may easily explain the decrease in 

 toughness after immersion in acid. For toughness implies a 

 certain ease of mobility of the particles. When a piece of iron 

 is bent the particles of one side are compressed, thus diminishing 

 the minute cavities between the fibres, while those of the other 

 side are stretched, and the minute cavities elongated. If 

 we fill these cavities with a liquid this mobility of the particles is 

 prevented, for the cavities cannot now be diminished m size and 

 the compression of the one side cannot now take place, conse- 

 quently the piece tears or breaks off just like a piece of frozen 

 rope. It will also explain the acid reaction of the moistened 

 fracture, and further, as hydrochloric acid is much more volatile 

 and of less specific gravity than sulphuric acid, it is only natural 

 to expect that the effect of immersion in hydrochloric acid will 

 pass off more rapidly than of immersion in sulphuric. This ex- 

 perience fully confirms. The author then gives details of a 

 number of experiments and their results bearing on the point 

 under discussion. — Results of certain Magnetic Observations 

 made at Manchester during the year 1873, t>y Prof. Balfour 

 Stewart, F.R.S. 



Glasgow 

 Geological Society, March 12. — A paper was read On some 

 Polyzoa f'-'-m the carboniferous limestone shales near Glasgow, 

 by Prof. Voung, P".G. S., and Mr. John Young, vice-president. 

 The authors described a new genus which they had established 

 under the name of Kliabdotncson, and which includes at least two 

 species hitherto referred to Ceriofora, namely, C. graci'is and 

 C. rhombifcra. The authors also described and exhibited 

 specimens of other two species of polyzoa, the one having the 

 habit of a Fenestdla, the other of a Glanconome, but both stiow- 

 ing the remarkable peculiarity of a series of eight denticles pro- 

 jecting horizontally over the cell aperture. For the fenestrated 

 species, they proposed to constitute a new genus — StelUpora. 

 The other they retained, meantime, in the genus Glauconomc. — 

 Mr. Robert Graig read a paper, the first of a series. On the 

 Fossils found in the carboniferous beds around Beith and Dairy, 

 with special reference to the position of their first appearance in 

 the bedi. These beds, he remarked, are highly fossiliferous, 

 and occur in the following general order : — (i) Lower limestone, 

 resting upon volcanic asli, 17 fathoms; (2) coal and ironstone 

 measures, resting upon the lower limestone, above 100 fathoms ; 

 (3) upper limestone, taking the Swindridgeor Highfield "post" 

 as the lower stratum, about 65 fathoms. Mr. James Dairon read 

 a paper on a new species of Retiolites (KetioUliS fibratus) found 

 by hmi last summer in the Moffat shales of the Lower Silurian 

 system of the South of Scotland. 



Paris 



Academy of Sciences, March 30. — M. Bertrand in the chair. 

 M. de Quatrefages presented to the Academy the second part of 

 his work (written in conjunction with M. Hamy, assistant natura- 

 list in the Museum) emitted " Crania el/iiiiia. The skulls of the 

 human races." The auihor made additional remarks on fossil 

 human races, caUing attention in particular to the race of Cro- 

 Magnon. The characters of this race are well exemplified in 

 the male and female remains discovered at Cro-.VIagaon in 1S68. 

 The male skull is remarkable for its capacity, gauging, according 

 to M. Broca, not less than 1,590 cent, cubes, a number sensibly 

 above the mean of all European populations. With the Cro- 

 Magnon remains the authors class several other specimens 0| 



human fossils from the same valley of Vezere, from Bruniquel 

 (caves of Lafaye and Forges), from the south towards the 

 Pyrenees (the cave of Aurigiiac), and from the cave of Gourdon 

 near Montrejeau. The same race is traced in the Menton 

 skeleton and beyond the Alps in the Cantalupo skulls and in that 

 from Isola del-Liri. In France again male skulls of the same 

 race have been excavated in Macon 'ais and Grenelle, while 

 Liege has furnished the celebrated Engis skull. During the 

 quaternary epoch it appears therefore that the Cro-Magnon race 

 had its head-quarters in the south-west of France, particularly in 

 the valley of Vezere, where the intellectual development can be 

 traced from station to station, possibly to the confines of civilisa- 

 tion. The authors think it probable that the earliest representa- 

 tives of the race will be found in Africa. — M. Pasteur made 

 some verbal observations on M. A. Guerin's recent communication 

 on the pathogenetic role of ferments in surgical maladies. — On an 

 apparatus invented by M. Moncoq for the operation of trans- 

 fusion of blood, by M. Bouley. — On theShydrometric service of 

 the basin of the Seine, by iVI. Belgrand. — MM. Daubree and 

 Brongniart presented a report on M. Renault's memoir, entitled 

 "Study of IheGenvi^Mydopteris." The reporters consider the con- 

 clusions arrived at of sufficient importance to warrant the publica- 

 tion of the memoir in the collections from foreign savants. — On 

 the integration of equations to the partial derivatives of the 

 second order, by M. A. Picart. — On the artificial production of 

 the phenomena of gaseous thermo-difTusion of leaves by means 

 of moist porous and pulverulent bodies, by M. Merget. The 

 author concluded by observing that tlie dynamical utilisation of 

 thermo-diffusive forces would resolve in a simple manner the 

 problem of the direct transformation ol solar heat (energy ?) into 

 mechanical work. — On some general facts which arise from com- 

 parative androgenesis, by M. A. Chatin. — Observations on the 

 disposition of the fibro-vascular bundles in leaves, by M. J. L. 

 de Lanessan. — On a method of photographic enlargement for 

 astronomical observations, by M. C. Zenger. The method pro- 

 posed is likely to be of service in photographing the forth- 

 coming transit of Venus. The author uses a mirror of 

 long focus instead of a lens to produce the sun's image, and to 

 prevent errors of irradiation and inflexion, proposes to photograph 

 the planet at its moment of passage across a point /i of a par- 

 ticular meridian of the sun. The enlarging process suggested 

 corrects aberration in the original photograph. — On an electro- 

 automatic whistle for locomotives, by MM. Lartigue and Forest. 

 — On the employment of luminous signals in geodesic operations, 

 by M. Laussedat. — The analysis (mattiematical) of an armed and 

 closed electro-magnetic circuit proves that electric induction does not 

 traverse conducting masses, by M. P. Volpicelli. — On the move- 

 ment of air in pipes, \y M. C. Bontemps. — On the action of 

 ammonia on acetone, by MM. Qichsner and Pabst. The authors 

 believe that the reaction gives rise to Staedeler's acetoniiie. — On 

 Egyptian blue, by M. H. deFontenay. — Experimental researches 

 on the influences which changes of barometrical pressure exert on 

 the phenomena of life, 13th note, by M. P. Bert. 



CONTENTS Pace 



British Quadrupeds 437 



SCLATER AND SaLVIN's "NoMENCLATOR AvIUM NeOTKOPI- 



calium" 438 



Our Book Shelf 438 



Letters to the Editor : — 



Microscopic Examination of Air. — Hubert Airy 439 



Animal Locomotion. — James Ward 440 



Rudimentary Organs. — George J. Romanes 440 



Lakes with two Outfalls —Colonel Greenwood 441 



A Beech Pierced by a Thorn Plant.— J. J. Murphy 441 



Kinetic Theory of the Dissipation of Energy.— By Prof. Sir 



William Thomson, F.R.S 441 



Livingstone's Wokk in Africa 444 



Soundings in the Pacific 445 



M. Charles Sainte-Claibe Deville's Weather Prognostica- 

 tions. — By W DE Fonvielle -. . 445 



On the Arrangement of the Skin-folds in the One-horned 



RhINOC ERI (W-//// ///«j/»fl.'iO«j) 446 



The Coming Transit of Venus, I. {With Ulustrations). By Prof. 



George Forbes 447 



The C^«//(fWff?' Expedition, III 45 



Notes 451 



Scientific Serials 453 



Societies and Academies ,.,,., 454 



