November 21, 1895] 



NA TURE 



7^ 



dykes had been converted into rocks of this character by dynamic 

 nietamorphism ; and Sir Archibald Geikie said that though he 

 would not venture to offer an opinion upon most of the disputed 

 questions in the geological structure of that area, he had seen 

 evidence sufficient to convince him that in the I'otstone Point 

 part of the coast the serpentine and horblende-schist formed, as 

 Mr. Teall maintained, the great complex which presented a 

 uirked coincidence of banding and had been plicated by one 

 > inmon series of movements. He could see no indication of 

 .lie serpentine being intrusive in the schists. — The " schistes 

 lustres " of Mont Jovet (Savoy), by Dr. J. W. Gregory. The 

 author gave a historj- of the controversy as to the age of the 

 " schistes lustres " of the Western Alps, making special refer- 

 ence to the views of Zaccagna and Bertrand concerning the 

 schists of Mont Jovet. Of these writers, the former maintained 

 that the rocks of the summit of the mountain are old rocks on 

 which the Carboniferous and Triassic strata were deposited un- 

 conformably ; while, according to the latter author, the rocks 

 forming the top of the mountain were laid down after those 

 which flank it. In his paper the present author gave the 

 results of an examination of the rocks of Mont Jovet recently 

 made by him. He contended that Lory and Zaccagna were 

 correct in identifying the central rocks of Mont Jovet as 

 " schistes lustres," for this conclusion is supported by their 

 liihological characters and the occurrence of basic igneous rocks 

 of the " pietre-verdi " type associated with them, and is not 

 opjxjsed to their stratigraphical relations. It was further main- 

 tained, as the results of the evidence collected by the author, 

 that the schists in question were older than the Trias. The 

 jirobabilities were in favour of the schists occupying the same 

 relation to the Carboniferous as they do to the Trias ; while the 

 close approximation of the schists to the former shows that the 

 schists are not the altered representatives of the neighbouring 

 Carboniferous beds, and it was therefore concluded that the 

 " schistes lustres" are pre-Carboniferous, but evidence by which 

 finally to assign them to any exact horizon before this date is 

 still wanting. 



Linnean Society, November 7. — Mr. C. B. Clarke, President, 

 in the chair. — Several volumes of Cryptogamic exsiccata, recently 

 received from Madame Weddell as a bequest from her late 

 husliand, a foreign member of the Society, were shown, and some 

 remarks made thereon by the Botanical Secretary. — A portrait of 

 the French naturalist Guillaume Rondelet, Professor of Anatomy 

 and Chancellor of the University of Montpellier 1545, recently 

 presented to the Society by Dr. H. Woodward, F.R.S., was 

 exhibited by the Zoological Secretarj', who gave an account of 

 his life and work, supplemented by remarks from the President. — 

 Mr. C. T. Druery exhibited and made remarks on a Scolopendrtum 

 raised by Mr. E. J. Lowe, bearing archegonia and antheridia 

 upon the fronds, constituting a more advanced phase of apospory 

 than any previously noted. Some remarks thereon were made 

 by Mr. George Murray. — Dr. Maxwell T. Masters exhibited 

 specimens of the fruit of Fyriis sorbiis, Aberia caffra, and small 

 Cocos aus/ralls, from the gardens of Mr. Thomas Hanburyat La 

 Mortola, Mentone, and some palm fruits of Cocos australis from 

 Naudin's garden at Antibes, Alpes Maritimes. — Mr. J. E. Harting 

 exhibited a specimen of the American yellow-billed cuckoo, which 

 had been picked up dead in a garden at Bridport, Dorsetshire, 

 on October 5, and gave some account of the species and pre- 

 vious occurrence in the British Islands. — A paper was read by 

 Colonel Swinhoe on mimicry in butterflies of the genus Hypolim- 

 itas, Hiibner. By means of a series of beautifully coloured lantern 

 slides, he showed the changes in mimetic forms in a single genus 

 of Nymphalid butterflies, from India through Arabia to Africa, 

 and from India through the Malay Archipelago to Australia, 

 commenting upon the resemblance they always bear in colour 

 and pattern to different forms of Danais and Etiplcca, insects 

 well known to l>e distasteful to birds and reptiles. — Mr. G. F. 

 Scott Elliot communicated a paper entitled " A revision of the 

 genus Penias,'" in which some account was given of the distribu- 

 tion of these plants in Africa, with a rectification of the 

 synonymy, and descriptions of five new species. The genus as a 

 whole showed in a remarkable manner the way in which local 

 species occur whenever a different climate restricts the distribu- 

 tion of a wide-ranging form, and several examples of this were 

 mentioned. A discussion followed, in which the President and 

 Mr. W. P. Hiern took part.— On behalf of Dr. A. G. Butler, an 

 abstract was read of a paper on butterflies of the genus Charaxes, 

 of which 159 species were recognised, nearly all of which are 

 represented in the National collection. Five species — Charaxes 



NO. 1360, VOL. 53] 



princeps, C. repetitiis, C. layardi, C. fervens, and C. coniger — 

 were described as new. 



Paris. 

 Academy of Sciences, November 11.— M. Marey in the 

 chair. —The following memoirs have been submitted to Com- 

 mittees : " Comparison of the French, English, and German 

 races by means of mortality tables," by M. Delauney. A note 

 concerning the weight of the atmosphere, by M. F. Delmas. 

 " On the formation of curved refractors and reflectors by means 

 of plane mirrors and transparent plane surfaces," by M. Moret 

 de Montjou. " The defence of the vine against phylloxera," by 

 M. Leroux (Tenes, Algeria). " A contribution to the study of 

 ferments," by MM. G. Niviere and A. Hubert. "The 

 Cartesian planimeter with tangential registration. A new 

 mechanical integrator of great precision," by M. Jos^ Ruiz- 

 Castizo. — On a problem concerning the determination of the 

 integrals of an equation to the derived partials, by M. E. 

 Goursat— On the unicursal types of two dimensions, by M. 

 Leon Autonne. — On the homogeneous differential linear 

 equations of which the general integral is uniform, by M. G. 

 Floquet. — On the construction of new magnetic maps of the 

 globe, undertaken under the direction of the Bureau des 

 Longitudes, by M. de Bernardieres. Seven survey expeditions 

 have been equipped with the most modern appliances, and sent, 

 under competent observers, to ascertain accurately the magnetic 

 elements at numerous stations, and an eighth will be started as 

 soon as the necessary instruments are obtained. The observing 

 stations are grouped broadly round the great oceans. — Some 

 effects of the synodic revolution of the moon on the distribution 

 of pressures in the season of summer, by M. A. Poincar^. — On 

 the hardening of extra-hard steels, by M. F. Osmond. With 

 steels containing 0*35 to about i '3 per cent, of carbon there is 

 a gradual increase of hardness with increase of carbon contents, 

 beyond i -3 per cent, the steel becomes softer. A description is 

 given of the method of investigating the structure of steel by 

 abrasion with a sewing needle and microscopic examination of 

 the scratch, and it is shown that the structure thus investigated 

 leads to the conclusion that hard steels consist of two inter- 

 penetrating types of steel, of which one is much harder than the 

 other. The same conclusion may be drawn by examination ot 

 etching figures, using iodine tincture or dilute nitric acid for the 

 attack. — On the silicides of nickel and cobalt, by M. Vigouroux. 

 These compounds of silicon and nickel or cobalt are produced 

 in similar ways to the chromium and iron silicides. They have 

 the composition SiNij, SiCo.^. They have a steel-grey metallic 

 appearance, a specific gravity of alxjut 7T, and are more fusible 

 than either of the constituents. Their properties in relation to 

 halogens, halogen acids, oxygen, alkalies, and potassium nitrate 

 are given in detail. — On crystallised normal calcium chromite, 

 by M. E. Dufau. At a sufficiently high temperature, chromic 

 oxide combines directly with lime to give a chromite of the com- 

 position CaO.CrjOg. This compound is stable at the highest 

 temperatures. It forms prismatic needles of metallic lustre, 

 transparent in thin crystals, and of a fine green colour. Its hard- 

 ness is 6, and specific gravity 4'8 at 18°. — On the alcoholates, by 

 M. H. Lescceur. Sodium ethoxide forms no stable alcoholate, 

 sodium hydrate appears to give the compounds NaOH.3C2HgO 

 and NaOH.CjHgO. — On the properties of emulsin from 

 mushrooms, by MM. Em. Bourquelot and H. Herissey. Emulsin 

 from different fungi of the mushroom type apjjears always 

 to be the same, and it cannot be affirmed to differ from the 

 emulsin of almonds. — Constancy of the freezing point of some 

 liquids of the organism. Application to the analysis of milk, by 

 M. J. Winter. The author establishes the isotonism of body- 

 fluids, more particularly of milk and blood-serum. " These 

 Hquids are equimolecular, and their molecular concentration is 

 the same among the diverse animal species examined." The 

 constancy of the freezing point of milk may be used as a means 

 of detecting adulteration with water. Blood-corpuscles, along 

 with their other functions, serve the purpose of regulating the 

 concentration of the blood serum. — On fermentations caused by 

 Friedliinder's pneumobacillus, by M. L. Grimbert. There exist 

 two types of Friedlander's pneumobacillus which are morpho- 

 logically alike, but differ in their fermentative action. The 

 pneumobacillus studied by Frankland has no action on glycerol 

 and dulcitol, whereas that from the Pasteur Institute attacks 

 these substances. — On the direct fixation, by vegetable fibres, of 

 certain metallic oxides, by M. A. Bonnet. — On the detached 

 crystalline rocks, probably of Tertiary age, in the Brian5on Alps, 

 by M. P. Termier. 



