524 



NATURE 



{April I, \^f^ 



tion of all thermometers rests, and the confusion which exists in 

 most of the«treatises on physics between the terms!: heat, sensible 

 heat, latent heat, and temperature. — M. Arthur Achard described 

 certain considerations relative to the useful effect of ma^eto- 

 electric machines, and spoke especially on some experiments 

 made by Prof. Hagenbach of Bale with a Gramme machine (see 

 Archhi des Sc. Phys. et Nat.,, vol. Ixiv. p. 332). — Prof. Schiff 

 spoke of the electric currents observed in animals. Most of 

 them proceed from the glands of the skin, which are veritable 

 electrical apparatus. If we destroy the skin or cauterise it, 

 currents are produced which are attributed to the muscles, but 

 which proceed from the movements of the animal. The observa- 

 tions were made on the protics. 



November 21, 1878. — Prof. Soret communicated the results 

 of his researches on absorption spectra by means of the eye, 

 especially with respect to ultra-violet radiations. He operated 

 on the eyes of oxen and calves, and he found that the ultra-violet 

 radiations were transmitted as far as the S line. The aqueous 

 humour allows them to pass as far as V. The vitreous sub- 

 stance has a transparency much greater than the aqueous 

 humour. — M. Raoul Pictet presented several considerations on 

 the passage to a liquid state of compressed gases, and in that 

 state the limit which is produced for each gas at a certain 

 pressure and a certain temperature. 



December 5, 1878. — M. J. M. Crafts showed a new thermoscope, 

 a description of which he recently published, and the air-reservoir 

 of which is only x\th of a cubic centimetre. From experiments 

 made with this instalment he concludes that the physical 

 characteristics of different bodies are much less dissimilar at high 

 than at low temperatures. — Prof. Schiff experimented before the 

 Society on a seismograph of M. Ziegler, consisting of a tube of 

 gold-beater's skin, with which he envelopes the member whose 

 variation of volume he wishes to measure, corresponding to the 

 beatings of the pulse. This large tube communicates its impres- 

 sions to a registering apparatus by means of a very narrow tube. 

 — Prof. Joh. Miiller gave an account of very delicate microscopic 

 observations made by him and M. Minks on lichens, and over- 

 throwing definitely the theoiy of Schwendler (See Arch, des Sc. 

 Jan. 1879, p. 49). i 



Paris 



Academy of Sciences, March 24. — M. Daubree in the chair. 

 —The following papers were read :— On the slow changes 

 undergone by wine during its conservation, by M. Bertheiot. 

 These observations relate to bottles of port ico and 45 years old 

 respectively, which the author analysed. Liter alia, the cane- 

 sugar in the older wine had disappeared almost completely ; and 

 there was very little in the other. The wines must have lost 

 more than a fourth of their acidity through etherification. The 

 amount of cream of tartar was much under the normal solubility. 

 The alcohol was in like proportion to that of recent port, there 

 had been little change in it, therefore, probably. As to gases, 

 one litre of the wine contained 12-4 cc. oxygen, and 32-3 cc. 

 nitrogen, without carbonic acid ; corresponding to normal satura- 

 tion of the wine by the gases of air. In saturation with oxygen 

 this old wine contrasts with recent Burgundy -vvines, which have 

 no trace of it in solution, but which contain CO2, while the old 

 ports have parted with this through diffusion.— Remarks on 

 some points of crystallogy, by M. Lecoq De Boisbaudran. 

 He makes inferences from the unequal resistances of differ- 

 ent faces of a crystal to change of state. The solubility of 

 the crystal must vary with its exterior form. The peculiar 

 mode of regeneration of mutilated crystals is easily ex- 

 plained ; also the influence of rapidity of gi-owth on relative 

 development of the different parts of a crystal, &c.— Communi- 

 cations on several geographical questions, by M. de Lesseps. 

 These relate to inter-oceanic canals and a conference on the 

 subject, to be held in Paris on May 15 ; news fi'om M. Soleillet 

 on the banks of the Niger, and from Serpa Pinto, announcing 

 important discoveries on the course of the Zambesi ; news also 

 from M. Roudaire at Gabes.— Addition to a previous note on 

 dammino- the Tiber at Rome, by M, Dausse.— Observations of 

 Brorsen'^s periodic comet, by M. Tempel.— Formula; relating to 

 perturbations of planets, by M. de Gaspans.— On resolving 

 equations, by M. Pellet.— On the solution in whole numbers of 

 the equation {i)«X^ + bY^ -V dX'Y^ -^ fX^Y + gXY^ = cZ\ 

 by M. Desboves.— Molecular vibrations in magnetic metals 

 durint^ passage of undulatory currents in these metals, by M. 

 Ader. Such vibrations are thus had in all the magnetic metals, 

 and give articulate sounds. To have them in all their intensity, 

 a mechanical action must be opposed to the wires or bars, 



especially the inertia of two heavy masses at their extre- 

 mities. The effects of these electrodynamic vibrations, and 

 the conditions of mechanical actions to be opposed to the 

 bars are quite the same as those the author has indicated 

 for electro-magnetic molecular vibrations. — On ytterbine, the 

 new earth of M. Marignac, by M. Nilson. — On scandium, a. ntw 

 element, by M. Nilson. The preparation of ytterbine (^vhich 

 he describes) furnished a substance with molecular weight 127*6 

 instead of 131, indicated by M. Marignac ; and M. Nilson was 

 led to suspect the presence of another earth, of lower molecular 

 weight, mixed with the product examined. The spectroscope 

 favoured this idea, and M. Thalen indicates the lines proper to 

 the spectrum of the new earth. The name given to the new 

 element is meant to recall its presence in gadolinite or enxenite 

 minerals, found only in the Scandinavian peninsula hitherto. 

 The atomic weight is under 90. M. Nilson remarks on some of 

 its chemical properties. — On the cyanosulphite of potassium, by 

 M. Etard. — Thermochemical study of alkalino-earthy sulphides, 

 by M, Sabatier. — On various alcoholic iodides and bromides, "by 

 MM. De Montgolfier and Giraud. — On the formation of aurine, 

 by MM. De Clermont and Frommel. — On the presence of lithine 

 in rocks and in the waters of seas ; consequences relative to 

 saliferous strata and to certain classes of mineral waters, by M. 

 Dieulafait. Lithine is as widely distributed as soda and potash, 

 and accompanies these two bases in all rocks of primordial forma- 

 tion. It exists in the Mediterranean and other seas in such 

 quantity that it can be recognised in the residue of evaporation 

 of even one cubic centimetre. It concentrates notably in the 

 sediments of salt marshes. Marls in small quantity give an in- 

 tense spectnim of lithine. All waters mineralised in the primor- 

 dial formation contain lithine, and all waters distinctly saline 

 contain it in exceptional proportion. — Resistance of germs of 

 certain organisms to the temperature of 100° ; conditions of their 

 development, by M. Chamberlaud. He describes two forms of 

 Bacillus, whose germs have this resistance ; boiling water several 

 minutes or even an hour will not kill them. — On the presence in 

 the blood and tissues, under spheroidal form, of certain liquids 

 not miscible in water and which have penetrated through the 

 lungs, by M. Poincare. Spirit of turpentine and nitrobenzine 

 are among the substances observed to have this effect. The fact 

 bears on respiration of noxious vapours by workmen. — Ana- 

 tomical and physiological study of nectaries, by M. Bonnier. He 

 rejects Darwin's theory of the rdle of nectaries. Nectariferous 

 tissues, floral or extra floral, emitting a liquid or not, form 

 special nutritive reserves in direct relation with the life of the 

 plant. — Experimental researches on the conditions of growth of 

 root hairs, by M. Mer. — On a new disease of the Rubiacese of 

 hothouses, by M. Comu. — On halos and parhelias seen in the 

 park of Saint Maur, by M. Renou.— On the unity of forces in 

 geology, by M. Hermite. 



CONTENTS Pagh 



Colour in Nature. By Alfred R. Wallace 501 



Geodesy 5°5 



Our Book Shelf :— ,. „ t, 



Legge's "History of the Birds of Ceylon. — R. Bowdler 



Sharpe 5°S 



Gevaert's " Structure et Modes de F^condalion des Fleurs " . . 5C6 



Letters to the Editor : — 



Deltaic Growth.— Pat. Dovle 5oo 



Atmospheric Pressure.— JoAO Capello . 500 



On the Pupation of the Nymphalidae —J. A. Osborn-e .... 507 



Tides at Chepstow.— John Yeats ; \Vm. Bowen 507 



Ice Pearls.— J. Shaw S08 



Unscientific Art.— John W. Buck ■;, ' tt" rJ " ' ^° 



Science and War— Signalling bv Sunshine. By H. Eaden 



Pritchard 500 



Flooding the Sahara 5o9 



The Longest Tunnel in the World 5o9 



Our Astronomical Colu.mn :— 



Brorsen's Comet S'o 



MiraCeti 5io 



The Minor Planet Hilda ^ ''"''' '^^° 



Experimental Researches on the Repulsion Resultijig from 



Radiation. By W. Crookes, F.R.S. (W'/M //A«/^«/z<"w) . • • 5" 



Meteorological Organisations SM 



Mycologv. By Rev. M. J. Berkeley s'a 



Geographical Notes * - | 



Notes ' * ■ cio 



Intellect is Brutes ^ . . . . • ■ • • ' = ^ 



The Plane of Polarisation Electromagneticallv Rotated in 



A Vapour • \2, 



University anb Educational Intelligence ^ 



Scientific Serials ^^i 



Societies and Academies 



