3IO 



NATURE 



[January 27, 1898 



of Orkney ; but Dr. Traquair showed that their nomenclature 

 had fallen into a state of chaos, principally by the unnecessary 

 multiplication of species upon deceptive characters, as well as, 

 to some extent, by the confusion of forms which actually were 

 distinct. The previous list was accordingly reduced from fifty- 

 eight to twenty-four, while, during the past ten years, Dr. 

 Traquair has added nine new species, making the entire 

 number up to thirty-three. Of these new species, three are 

 described for the first time in the present paper, namely, 

 Hoinocanthus crasstis and Asterolepis orcadensis, from Orkney ; 

 Cheincatithus striatus, from Caithness. The rest of the paper 

 consisted of an enumeration of the genera and species of Or- 

 cadian fossil fishes, their synonymy, and the localities in which 

 they are found in the three areas — Moray Firth, Caithness, and 

 Orkney. No fishes have been found as yet in the Orcadian 

 beds of Shetland. Of the thirty-three species, twenty-seven 

 occur in Caithness, twenty-four in Orkney, and seventeen in 

 the Moray Firth beds, the small number in the last-named area 

 being apparently due to the absence of certain geological 

 horizons, which are represented both in Orkney and in Caith- 

 ness. The paper was illustrated by limelight pictures of the 

 principal forms of Orcadian fossil fishes, both as they occur in 

 the rock and as restored by the author. 



Mathematical Society, January 14. — Mr. J. B. Clark, 

 President, in the chair. — The trisection of a given angle, by 

 Mr. Lawrence Crawford. — The centre of gravity of a circular 

 arc, by Mr. G. E. Crawford.— A demonstration of the apparatus 

 used in practical skiagraphy by the Rontgen rays was given by 

 Dr. Harry Rainy. 



Paris. 



Academy of Sciences, January 17. — M. Wolf in the chair. 

 — Notice of the life and works of M. d'Abbadie, by M. Hatt. — 

 On some results relating to the phenomena discovered by M. 

 Zeeman, by M. A. Cornu. Further improvements in the methods 

 of observation give results not altogether agreeing with those 

 of the original experiments. The action of the magnetic field 

 upon the period of vibration of the radiations from a luminous 

 source appears to depend not only upon the chemical nature of 

 the source, but also on the nature of the group of rays in the 

 spectrum to which each radiation belongs, and on its function 

 in this group. If the direction of the field observed is normal 

 to the lines of force, each ray becomes four, and not three as 

 originally announced by Dr. Zeeman. — Remarks by M. Henri 

 Becquerel on the preceding communication. — On the separation 

 and estimation of iodine, bromine, and chlorine, by M. Ad. 

 Carnot. The separation is based upon the removal of iodine by 

 carbon bisulphide after acting upon the mixture with nitrous 

 vitriol ; the bromine is then set free by chromic acid at 100°, 

 and removed by the same solvent. J'airly satisfactory analytical 

 results are appended. — On the decimal hour system, the 

 divisions of the day and the circle, and the geographical table, 

 by M. Henride Sarrauton. — Occultation of the Pleiades by the 

 moon, January 3, 1898, observed at the University of Paris, by 

 M. G. Bigourdan. — Occultation of the Pleiades group, observed 

 at Lyons, by M. Ch. Andre. — On the four large planets, by 

 M. Emile Anceaux. Certain simple numerical relations have 

 been found to exist between the masses and major axes of orbits 

 of Jupiter, Neptune, Saturn, and Uranus. — On the representa- 

 tion of uniform analytical functions, by M. Paul Painleve. — On 

 the convergence of series representing the integrals of differ- 

 ential equations, by M. Paul Staeckel. — On the irregular 

 integrals of linear differential equations, by M. J. Horn. — On 

 the existence of integrals of a partial system, determined by 

 certain initial conditions, by M. Riquier. — On the systems of 

 triply orthogonal surfaces where the surfaces of a family 

 admit of the same spherical representation of their lines 

 of curvature, by M. Maurice Fouche. — On the basis of 

 projective geometry, by M. H. G. Zeuther. — On the 

 problem of the cooling of a heterogeneous bar, by M, W. 

 Stekloff. — On gas mixtures, by M. A. Leduc. The author 

 proposes to replace Dalton's law, that the pressure of a mixture 

 of gases is equal to the sum of the pressures that each would 

 occupy in the same receptacle, by another, that the volume 

 occupied by a mixture of gases is equal to the sum of the volumes 

 that the component gases would occupy under the conditions of 

 pressure and temperature of the mixture, the two statements 

 being only identical when Boyle's law holds exactly. — De- 

 termination of the density of gases on very small volumes, by M. 

 Th. Schloesing, jun. The method described gives very fair 



NO. 1474. ^OL. 57] 



results with quantities of gas as small as 6 c.c, and requires 

 neither the use of a barometer nor a balance. A column of the 

 gas whose density is to be determined is balanced hydrostatically 

 against a column of gas of known density and absorbable by 

 caustic potash, such as carbon dioxide. The manipulation and 

 calculation are extremely simple. Further details and numerical 

 results will be given in a later paper. — On an apparatus called the 

 hermetical pourer, by M. R. Personne de Sennevoy. With the 

 apparatus in question, a diagram of which is given, a portion of 

 a liquid contained in a hermetically closed vessel can be ex- 

 tracted without introducing any other fluid into the vessel. — 

 On the thermodynamic potential, by M. A. Ponsot. — -On the 

 spectrum of the kathode rays, by M. Birkeland. — On the 

 spectrum of cadmium in a vacuum tube, by M. Maurice Hamy. 

 The wave-lengths of the ten principal lines were measured with 

 an accuracy of six significant figures. — On the absolute value of 

 the magnetic elements on January i, 1898, by M. Th. Moureaux. 

 The calculations are made for the elements at Paris, Nice and 

 Perpignan. — Contribution to the study of the electric furnace, by 

 MM. Gin and Leleux. — New method for measuring the intensity 

 of a magnetic field, by M. E. Bouty. A liquid conductor is 

 allowed to flow normally to the lines of force in the field to be 

 measured. The constant electromotive force induced in the 

 liquid vein is measured by means of the capillary electro- 

 meter. It was found that tap water served very 

 well for the conducting liquid, and by increasing the 

 velocity of flow the sensitiveness of the method can be 

 increased almost indefinitely. The fields measured were of the 

 order of o 5C.G.S. units. — On a thermometric mercury ammeter, 

 by M. Ch. Camichel. A thermometer bulb is placed in a glass 

 tube slightly larger, and the narrow annular space filled with 

 mercury through which the current is passed. The instrument 

 described measures up to 2 amperes with an approximation of 

 I /200th. — Discharge by the Rontgen rays. Secondary effect, 

 by M. Jean Perrin. The hypothesis provisionally put forward 

 of a superficial phenomena is now shown to be improbable. — On 

 the electrical resistance of crystallised silicon, by M. Fernand 

 Le Roy. The resistance of silicon is about 1300 times that of 

 electric light carbon, and diminishes on heating, a decrease of 

 about 40 per cent, corresponding to a rise of 800° C. — On some 

 new compounds of the cerite metals, by M. Andre Job. — On 

 aldehyde ammonia, by M. de Forcrand. Calorimetric data of 

 the solutions of this substance. — On ;8-isopropyl-7-acetylbutyrate 

 of ethyl and on the stereoisomeric acids derived from it by con- 

 densation, by MM. Ph. Barbier and V. Grignard. — On the 

 oxidation of ammonia compounds by the ferments of the soil, 

 by M. E. Demoussy. Under the influence of the bacteria of 

 the soil the amines are oxidised to ammonia, and this goes to 

 nitrite and nitrate in the usual manner. The more complex the 

 amine the slower is the course of oxidation. —Bacilli of beriberi, 

 by M. Gustave Nepveu. Three forms of bacilli differing in size 

 (8 yu, 3 /u for the two larger) were found, but it is not quite certain 

 that these are distinct forms. — On the structure of the cirrophore 

 in the Polynoidia, by M. G. Darboux, jun. — On the elongations 

 of the anterior portion of the body of the Prosobranchia and 

 their influence upon the corresponding region of the digestive 

 tube, by M. Alex. Amaudrut. — On a cselomic gregarian 

 presenting a phase of asporulic multiplication in the evo- 

 lutive cycle, by MM. Maurice CauUery and Felix Mesnil. 

 The new species is a parasite in the general cavity of 

 Dodecaceria concharum, and is named Gonospora iongissinia. 

 — Sex and molecular dissymmetry, by M. Felix Le Dantec. — 

 Some remarks by M. Edmond Perrier on the preceding paper. — 

 On the supposed chloragogenesis of the general cavity of the 

 Ophelias, by MM. J. Kunstler and A. Gruvel. — On the existence 

 of a malacological polybathic fauna at great depths in the Atlantic 

 and Mediterranean, by M. Arnould Locard. Outside the well- 

 defined littoral zones there exists both in the Atlantic and 

 Mediterranean a fauna capable of living and developing at depths 

 of over 2000 metres, to which the name polybathic is given. This 

 fauna contains many Gastropods, and is especially rich in 

 Scaphopods and Lamellibranchs. — On the origin of the double 

 sheath of the root of Tropcclum, by M. Camille Brunotte. — On 

 the preparation of gentianose, by MM. Ed. Bourquelot and L. 

 Wardin. — On the germination and hibernal fructification of the 

 truffle, by M. A. de Gramont de Lesparre. — On the mineral 

 layers of oolitic iron of the new basin of Briey, by M. Georges 

 Rolland. Complete geological sections of these important beds 

 of Meurthe-et-Moselie are given. — On the caverns of Sauve 

 (Gard), and the form of the reservoirs of springs and calcareous 



