28o 



NA TURE 



[Fed. 3, 1876 



Geneva 

 Physical and Natural History Society, Jan. 6. — M. 

 Ernest Favre took up the discussion which has existed for ten 

 years among geologists and paUvontologists on the limit of the 

 Jurassic and Cretaceous beds in the Alps, where tlie beds arc not 

 separated, as in the Anglo- Parisian basin, by freshwater deposits. 

 Oppel, in 1865, gave the name of Tithonic sta;;e to the beds con- 

 taining Cephalopodous and Coralline fauna-, and which are 

 found in the upper part of the Jurassic system. Geologists, 

 mostly French, of whom M. Plebert is the best known repre- 

 sentative, assigning a part of these deposits to the Cretaceous 

 formation and regarding the zone of Ammonite's taiuilobalus as 

 Oxfordian because it is covered by Coraliferous beds, almit that 

 there is in the Alps a great gap between the Oxfordian and the 

 Cretaceous formations. German and Swiss geologists, on the 

 contrary, find in the Alps the complete series of the Upper 

 Jurassic system of the Jura. They have shown that Coraliferous 

 is developed in nearly all the horizons of these beds, and not only 

 in that to which D'Orbigny has given the name of Coralline stage, 

 a name which ought to be suppressed ; that the highly developed 

 zone of Ammonues tenuilobatus in the Alps is Kimmeridgian, and 

 that the Tithonic beds belong to the Jurassic formation. M. 

 Favre has found in the Western Alps of Switzerland the complete 

 series of these strata ; he has described it in a memoir on the 

 Upper Jurassic formation Voirons. This series has the following 

 four divisions from below upwards : — I. The Oxford formation, 

 properly so called. 2. The zone of Avimonites bimammattis, 

 which contains many species of the zone of Amm. iransversarius. 

 3. The zone of Ammonites Acanthicits and A. tenuilobatus 

 (Astartian). 4. Tithonic beds, which are the equivalent of 

 the Solenhofen beds. The Voirons formation includes Nos. 2 

 and 3. The passage from the Jurassic to the Cretaceous 

 systems has been worked in a part of the Alps, without 

 any interruption in the four divisions ; and if we cannot find all 

 the equivalents of the fossiliferous beds of the Jurassic basin, it 

 should be remembered that the deposits have been placed in the 

 former region in conditions different from those which have 

 reigned in the second. 



Paris 



Academy of Sciences, Jan. 24. — Vice- Admiral Paris in the 

 chair. — The following papers were read : — On the decomposition 

 of water by platinum, by MM. Sainte-Claire Deville and Debray. 

 When a mixture of cyanide of potassium with spongy platinum 

 is heated in a glass vessel raised to 500° or 600'^ near a dish ot 

 tepid water, in vacuo, large quantities of hydrogen are produced, 

 and a double cyanide of platinum and potassium. A concen- 

 trated solution of cyanide of potassium attacks platinum at the 

 boiling temperature. — Action of monohydrated sulphuric acid on 

 alcohols, by M. Berthelot. He measures the heat liberated in 

 such reactions. — New case of aphasia or loss of speech, arising 

 from loss of the co-ordinated movements necessary for the act of 

 pronunciation of words, without any lesion of the intellectual 

 faculties, by M. Bouillaud. — On the falling in of the Cirque de 

 Salazie, in the Isle of Reunion, by M. Sainte-Claire Deville.— 

 On the star 70 p Ophiuchus, by M. Tisserand. He seeks to 

 determine the orbit from 213 observations, comprising an entire 

 revolution. — Report on the numbers of the Revue cfArtillerie 

 submitted to examination of the Academy by the Minister of 

 War.— Application of the mechanical theory ot heat to the study 

 of volatile liquids ; simple relations between the latent heats, 

 atomic weights, and tensions of vapours, by M. Pictet. Inter 

 alia, latent heat multiplied by atomic weight (temperature and 

 pressure being the same) gives a constant product. The differ- 

 ence of latent heats at any two temperatures multiplied by atomic 

 weight is a constant number. The latent heats of all liquids 

 are multiples of the specific heats. — Action of ammonia on 

 rosaniline, by M, Jacquemin. — Researches on the constitution ot 

 collagenous matters, by MM. Schiitzenbeiger and Bourgeois. — 

 Map of the globe in gnomonic projection on the horizon of the 

 North Pole, by M. Thoulet. — On the action of cold on milk, and 

 the products obtainable from it, by M. Tisserand. The rising 

 of cream is quicker, and the volume of it .greater, the nearer 

 the temperature has been brought to zero ; also the yield of 

 butter is greater, and , the mUk creamed.j butter and cheese 

 are of better quality, the lower the temperature. The common 

 practice might be greatly improved in this respect. — On the 

 covariants of binary forms, by M. Jordan. — On a particular class 

 of left inscriptible polygons, by M. Serret. — Magnetic actions on 

 the rarefied gases in Geissler tubes (fourth note), by M. Chau- 

 tard. The gaseous matter probably undergoes attracdon or 



repulsion under action of the magnet, resulting in compression 

 against the side of the tube and change in the physical state of 

 the luminous stream. The alteration of the si)sctrum by mag- 

 netism is more marked, the greater the diameter of the tube 

 (from I'o mm. to I cm. in these experiments). With fluoride of 

 silicium Geissler tubes, the author appears to find some indi- 

 cation of a new chemical reaction under magnetic influence. — 

 On the spectrum of nitrogen and that of alkaline metals in 

 Geissler tubes (continued), by M. Salet. He suggests that the 

 lines described by Mr. Schuster in 1872 may have been those 

 of sodium vapour. — On the action of heat in magnetisation, by 

 M. Favre. Three phenomena observed: — !. Conservation of 

 magnetism at any temperature, when the latter was maintained 

 constant. 2 . Diminution of the magnetism in cooling,, at first 

 slow, becoming very rapid after a time variable with the 

 temperature of magnetisation. 3. Increase of the quantity 

 of magnetism that remains after cooling, when the magnet is 

 heated anew. — Note on a new system of electric lamp, with 

 independent regulator, by M, Girouard. — On a new method of 

 recording the movements of blood-vessels in man, by M. Mosso. 

 We shall notice this separately. — Note on the development of 

 the Salmaci7ia Dysten, Hux., by M. Giard. Several characters 

 bring the embryo of Salmacina near that of Molluscs. The 

 divergence between Molluscs and Annelids commences only after 

 the Trochosphsera stage, and even after this there are many 

 agreements. The parentage of Molluscs and Annelids is cer- 

 tainly nearer than that of the latter with Arthropods. The 

 origin of the three groups must be sought among the Rotifers. — 

 New fossil mammifers from the deposits of phosphate of lime at 

 Quercy, by M. Filhol. — Influence of various elements of manures 

 on the development of the beet, and its saccharine richness, by 

 M. Joulie. 



French Physical Society, December 17, 1875. — M. Jamin 

 communicated the formula; which he has established to represent 

 the distribution of magnetism in magnets furnished with con- 

 tact armature. If the armature is indefinite, the magnetic 

 intensity in the soft iron is represented by an exponent of 

 a single term, as in the case of magnets of very great length ; if i 

 the armature is shorter the intensity is given by the sum of the , 

 two exponents. The diminution of intensity in each poin: of 

 the magnet follows the same law, and the constants of the formula; 

 may be determmed by noting on the one hand that the total loss 

 of magnetism on the magnet is equal to the gain in the arma- 

 tmre, and on the other hand, that the intensity at the point of 

 contact is the aame i» the armature and in the magnet. 



Vienna 



Imperial Academy of Sciences, Dec. 16, 1875. — ^^^ 

 differential air thermometers, by M. Pfaundler. Berthelot's 

 air thermometer with capillary manometer has the drawback, 

 that its data depend on the existing barometric state. M. 

 Pfaundler seeks to obviate this by his differential air thermo- 

 meters. He gives various constructions of these. — On new fish 

 species from the collections of the Imperial Zoological Museum, 

 by M. Steindachner. Mostly species of siluroids from the Bay 

 of Panama, &c. — On the flow of stratified clay under bodies 

 pressed into it, by M. Obermayer. 



CONTENTS 



Page 



The University of London and School Examinations .... 261 



Guthrie's " Magnetism and Electricity " {iVith Illtistrations) . 261 



Two Amateur Explorers 264 



Our Book Shelf 265 



Letters to the Editor : — 



Tfie Article " Birds " in " Encyclopaedia Britandica." — Prof A. H 



Garrod 266 



The Difficulties of tlie Public Analysts.— \V. Mattieu Williams 266 



Science in Hastings —Alex. E. Murray 267 



Our Astronomical Column : — 



TheTolalSolar Eclipse of 1876, Sept. 17-18 268 



Minor Planets 268 



The Second Comet of 1702 368 



Prof. Tyndall on Germs 268 



The Occurrence and Manufacture of Flint Skin-Scrapeks 

 from New Jersey, U.S.A. By Dr. Charles C. Abbott. (IrVith 



Illustrations) 270 



The Recent Butter Cask 271 



Natural History of St. Helena. By T. D 272 



Notes =72 



The Loan Exhibition of Scientific Apparatus 274 



Prof. Nordenskjold on the Jenisei 275 



Scientific Serials 277 



Societies AND Academies 277 



