April 20, 19 16] 



NATURE 



175 



{X)tassiuni chloride of equimolecular concentration 

 have almost the same electric conductivity. They are, 

 therefore, of interest in connection with the direct 



, measurement of ionic velocities. The paper describes 

 a simple method of observing their common boundary. 

 It is only necessary to add a little mercuric chloride 

 to the potassium chloride solution. An extremely thin 

 layer of mercuric iodide then forms where the t\vo 

 solutions meet. The method is particularlv convenient 



; for lecture purposes, and an approximate value of the 

 ionic velocity can be obtained in a few minutes. The 

 paper gives examples of the use of the method. The 

 current is first passed in the direction which causes 

 the iodine ions to travel towards the chloride. The 

 chlorine liberated at the anode in this case supplies a 

 means of re-determining the velocity of the ions when, 

 the current being reversed, thev move in the opposite 

 direction. 



Edinburgh. 

 I Royal Society, March 20.— Dr. J. Home, president, 

 m the chair.— Dr. C. Davison : The Ochil earthquakes 

 of the years 1900-19 14. The district chiefly affected 

 lies on the south of the Ochil Hills, and includes 

 jDunblane, Bridge of Allan, Menstrie, Alva, Tilli- 

 icoultry, and neighbouring places. The earthquakes 

 began m 1900, but did not become frequent until 

 1905, when ten shocks were felt. There were nineteen 

 |;n 1906, thirteen in 1907, seventeen in 1908, eighteen 

 m 1909, nineteen in 1910, eight in 191 1, seventy-four 

 tin 1912, two in 1913, and one in 1914. The total 

 number in the fifteen years was 186. The three earth- 

 quakes of September 21, 1905, October 20, 1908, and 

 jVIay 3, 1912, were of unusual strength, and were 

 ielt over areas of nearly a thousand square miles, 

 jrhe last of the three was so strong that a slight 

 Increase of intensity would have resulted in damage 

 jO property. The earthquakes seem to have been due 

 10 small movements along the great fault whicfi skirts 

 ine southern slope of the Ochil Hills. There was 

 jvidence that the origins passed westwards as time 

 kogressed. There were indications both of an annual 

 md of a semi-annual periodicitv.— Dr. C. G Knott • 

 Mathematical note on the fall of " small particles 

 hrough liquid columns.— W. R. Smellie : Apractoleidus 

 erettpes. This Plesiaur was collected from the 

 Jxford Clay by H. N. Leeds, and acquired for the 

 luntenan Museum by Prof. J. W. Gregory. The 

 lajor portion of the skeleton is present, the bones 

 eing m excellent preservation. In some respects the 

 nimal is intermediate between Cryptodeidus axon- 

 ^nsts and Tncleidtis Seeleyi; but in others it shows 

 I higher degree of organisation than either of these 

 pecies For example, in the fore oaddle, the humerus 

 esembles that of Cryptodeidus, except in the facets 

 n the distal end ; but it articulates with four elements 

 s in iricleidus. In this wav it combines the advan- 

 iges of both, and gives a broader and more efficient 

 addle. Ihe shoulder girdle is typically efasmo- 

 surian, and the clavicles are reduced to thin, func- 

 onless plates, lying wholly on the visceral surface 

 ; the scapulae. Both pectoral and pelvic girdles show 

 ,ie animal to have been of great breadth. A high 

 l-gree of ossification is a riotable characteristic of 

 lie skeleton. 



Dublin. 

 Royal Dublin Society. March 28.-Prof. Hugh Ryan 



r«;nn f '""'••Tr^.'''^^- ^^'- ^'"^"- The subsidence of 

 mZ\ oscillations of nickel and iron wires when 

 mjected to the influence of transverse magnetic fields 

 to »oo c g.s. units. Experiments on the subsidence 

 torsional oscillations of nickel and iron wires in 

 ansverse mnernet.c fields, both direct and alternating 



Jn^ fu'''''"'T -""^ ^ ""'^^ ^hows that the damp: 

 •g of the oscillations is increased as compared with 



NO. 2425, VOL. 97] 



the oscillations with no field round the wire. When 

 the frequency of the alternating transverse magnetic 

 field is increased eight times, the damping of the 

 torsional oscillations is decreased in nickel and in- 

 creased in iron wire. — Prof. VV. Brown : The change 

 of length in nickel wire due to transverse magnetic 

 fields, direct and alternating. The maximum expan- 

 sion of nickel wire, due to transverse magnetic fields, 

 both direct and alternating, takes place in a field of 

 about fifty units, the longitudinal load on the wire 

 being 2 x 10* grammes per sq. cm. For higher fields 

 the expansion diminishes gradually, and for a trans- 

 verse field of about 1000 units there appears to be 

 neither expansion nor contraction. — Prof. Sydney 

 Young : The boiling-points and critical temperatures 

 of homologous compounds. The formulae of Walker, 

 Boggio-Lera, Ramage, Ferguson, and Young are 

 compared, and it is shown that the author's formula 

 gives the best agreement between the calculated and 

 observed boiling-points of the normal paraffins, data 

 for which, including some recently determined in 

 America, are available from CH^ to C,,H„. The 

 American chemists have also determined the critical 

 temperatures of normal and i.Jo-butane, and the rules 

 regarding the deviations from Guldberg's law, 

 Te/Ti = constant, brought forward by the author in 1908 

 (" Stoicheiometry," p. 183), are found to hold good. 



Paris. 

 Academy of Sciences, April 3.— M. Camille Jordan in 

 the chair. — G. Bigourdan : The discovery of the nebula 

 of Orion by Peiresc. This discovery w-as for a long 

 time attributed to Huyghens (1659), and later to 

 Cysatus (16 19). Proof is now given of the observa- 

 tion of this nebula by Peiresc (1610). — Pierre Duhem : 

 The conditions which determine electrical movement 

 in a system of several dielectrics. — M. de Sparre : The 

 influence of atmospheric conditions on the trajectories 

 of long-range projectiles. For the 406 cm. German gun, 

 with a maximum range of 40 kilometres, it is calcu- 

 lated that an increase of temperature of 13° C. or a fall in 

 the atmospheric pressure of 10 mm. causes an increase 

 of range of 1792 metres. — Gaston Julia : The reduction 

 of positive quaternary quadratic forms. — Henn,k 

 Arctowski : The variations of mean heliographic latitude 

 of the sun-spots. — J. Vallot : The law which connects 

 the calorific absorption of a cell with the refractive 

 indices of the material of the cell and of the liquid 

 which it contains. The method described in an earlier 

 paper for determining the corrections due to the walls 

 of the cell is applicable to most colourless liquids, but 

 fails for highly viscous or coloured liquids. A method 

 is outlined for dealing with these exceptional cases. — 

 E. Leger : The isomeric acetyl derivatives of nataloin 

 and homonataloin. — J. ChiflBot : The sexual variations 

 of the inflorescences and flowers in cultivated 

 Codiaeum. — Mile. Trouard-Riolle : Cross between a wild 

 crucifer and a cultivated crucifer with a tuberised root. 

 The plants used in the experiments were Raphanus 

 Raphanistrum and cultivated varieties of Raphanus 

 sativus. The tuber formation on the wild plant was 

 readily produced by crossing. The wild type tends to 

 become preponderant in the descendants of the hvbrid 

 plants. — Jules Wolfl : A substance coagulating i'nulin 

 and accompanying it in plant tissues. This ferment 

 was isolated from chicon,- roots and from dahlia 

 tubers, and named inulo-coagulase. — Emile Belot : The 

 possible origin of terrestrial magnetism. — Ph. Flajolet : 

 Perturbations of the magnetic declination at Lyons 

 (Saint-Genis-Laval) during the fourth quarter of 1915. 

 — Marcel Bandouin : The early date of the jaw found 

 at La Naulette. From a studv of the two" premolars 

 the conclusion is drawn that Homo Natileitensis dates 

 probably from the Pliocene epoch. — A. Borissiak : In- 

 dricotherium, a new genus of giant rhinoceros. The 



