March 29, 1900] 



NATURE 



531 



Edinburgh. 



Royal Society, February 19. — Prof. McKendrick in the 

 chair. — Sir John Sibbald read a paper on the statistics of suicide 

 in Scotland. The various tables were arranged to bring out 

 such features in the statistics of suicide as the influence of sex 

 and age, of season, of locality, of town and country, and so on. 

 The prevalent idea that statistics proved an increasing tendency 

 in suicide was shown to be a too hasty deduction from the 

 figures. When the statistics of suicide by hanging — the one 

 method in which there was very little chance of mistake — were 

 compared for the last fifteen years and for the preceding period 

 of fifteen years, the number of suicides per million was exactly 

 the same. Then a careful scrutiny of the returns for deaths by 

 accident showed that the apparent increase in suicide by such 

 methods as drowning, shooting, poisoning, &c. , was balanced 

 by a decrease in deaths by accident due to the same causes. 

 It would, therefore, appear that the apparent increase in suicides 

 in the last fifteen years was due, not to a real increase in 

 suicide, but to improved methods of discriminating between 

 suicide and accident. The statistics clearly established the fact 

 that the suicidal rate was less in the western than in the eastern 

 counties of Scotland, a fact which Dr. Clouston, in the after- 

 discussion, explained as being in all probability due to difference 

 of race, the greater Celtic element in the west producing, not 

 necessarily a less suicidal disposition, but a less determined 

 carrying out of the deed of self-destruction. 



March 5. — Prof. Duns in the chair. — A paper, by Dr. Thomas 

 Muir, on certain aggregates of determinant minors, was taken as 

 read. — Mr. John Aitken, F. R. S., communicated a paper on the 

 dynamics of cyclones. Attention was first drawn to the con- 

 ditions under which cyclonic motion was developed both in air 

 and in water ; and the dynamic principles underlying the pro- 

 duction of the phenomenon were illustrated by means of a neat 

 arrangement of balls hung at the ends of two parallel wires, the 

 whole being capable of rotation about a central vertical axis. 

 When drawn together by pulls along threads which passed 

 through the axis of rotation, the two balls were made to spin 

 round one another with a rapidly increasing angular velocity, 

 thus illustrating the important principle of the conservation of 

 moment of momentum. By a simple modification, the apparatus 

 could be made to illustrate the principle of the conservation of 

 energy. Mr. Aitken emphasised the importance of giving in- 

 creased attention to the anti-cyclonic distributions which in a 

 sense may be regarded as playing, relatively to the accompany- 

 ing cyclonic distributions,, the s^me rdle as is played by the 

 condenser relatively to the boiler of a steam engine. The 

 direction and rate of movement of a cyclone was shown to be 

 determined by the position and configuration of the region 

 where the isoliars were closest ; a cyclone whose isobars form a 

 set of concentric circles having little or no translatory motion. 

 This characteristic was explained by the author as due to the 

 direct influence of the anti-cyclonic vortex. Many of the 

 features of cyclones were illustrated by means of an ingenious 

 apparatus in which the necessary upward draught was produced 

 in a tall chimney, the whirls of air developed beneath being 

 made visible by the use of sal-ammoniac fumes. The crossing 

 of currents at different heights was beautifully demonstrated. 

 In conclusion, Mr. Aitken referred to the physiological effects 

 observed in the front area of a cyclone, and thought that these 

 might be explained as due to the impure air rising from the 

 ground. In the after-discussion, Prof. Crum Brown drew 

 attention to the experiments by which Prof. Hunter Stewart 

 had established the fact that the soil breathed out a great deal 

 of carbonic acid gas, and no doubt other emanations as well. 

 Mr. Omond pointed out thit the dissimilarity as regards relative 

 dimensions between Mr. Aitken's model and the real cyclone 

 should make us very cautious in applying the results obtained 

 with the model to the explanation of cyclonic effects. Dr. 

 Buchan said that, although most of the storms of the north-west 

 of Europe travelled westwards and were characterised by high 

 westerly and south-westerly winds, there were occasionally 

 cyclones which travelled eastwards, and these were always 

 characterised by high east winds. Dr. Knott took the oppor- 

 tunity of protesting against the tendency of speaking of a cyclone 

 as .something independent of the winds that really constituted 

 it. Given a cyclonic condition moving through the air, it is 

 obvious that the strongest winds wilf be on the whole in the 

 direction of that movement, and consequently the isobars will 

 be closest where the associated wind has this direction. It is 

 merely expressing the same truth in different ways to say that a 



NO. 1587, VOL. 61] 



westward travelling cyclone in our latitudes has its isobars 

 closest to the south and is characterised by high west winds, 

 that a slow moving or motionless cyclone has a symmetrical 

 arrangement of isobars, and that an eastward travelling cyclone 

 has its isobars closest on the north and is characterised by high 

 east winds. — Dr. W. G. Aitchison Robertson read a note on 

 the activity of saliva in diseased conditions of the body, being a 

 continuation of a previous paper. In many diseases the digestive 

 activity of saliva on starchy foods underwent a great diminution. 

 This was particularly the case in disorders of the stomach, and 

 the importance of selecting a proper dietary in such cases was 

 insisted on. In many instances a more thorough examination 

 of the saliva than is customary would almost certainly lead to 

 valuable conclusions, and an examination of this kind had the 

 great merit of l^eing extremely easy. 



Paris, 

 Academy of Sciences, March 19. — M. Maurice Levy in 

 the chair. — Forces related to the state of perfect elasticity that 

 dynamic contraction creates in the muscle substance. The 

 physiological work intimately constituted by this creation, by 

 M. A. Chauveau. — On liilear partial differential equations of 

 the second order with constant coefficients, by M. J. Coulon. — 

 On differential systems with fixed critical points, by M. Paul 

 Painleve. — On multiplex telegraphy, and a differential telc' 

 microphonic relay, by M. E. Mercadier. A description of a 

 new microphonic relay by means of which it is possible to send 

 a large number of messages .simultaneously over the same wire. 

 Between the two end stations, intermediate stations working 

 together with the extremes can be interposed without any 

 difficulties arising. — Relations between the electrolytic con- 

 ductivity and internal friction of saline solutions, by M. P. 

 Massoulier. Solutions of sulphate of copper in solutions of 

 glycerine and water of various strengths were employed. 

 The resistances were measured both by the Lippmann 

 electrometric method and by the telephone with alter- 

 nating currents, the viscosity by Poiseuille's method. At 15° . 

 the rises of resistance and viscosity with increase of glycerine 

 are proportional, but this does not appear to hold at 0° C. — On 

 a quartz thermometer for high temperatures, by M. A. 

 Dufour. Two quartz thermometers have been prepared, one 

 containing tin, capable of measuring temperatures between 

 240° and 580° C. , and another containing mercury. The study 

 of the zero residues in the quartz-mercury thermometer is under 

 consideration. — Fluorescence of certain metallic compounds 

 when submitted to the Rontgen and Becquerel rays, by M. 

 Paul Bary. Numerous salts of the metals of the alkalies and 

 alkaline earths are divided into two groups according as they 

 were found to be fluorescent or non-fluorescent in the X-rays. 

 The substitution of a radio-active substance for the Crooke's 

 tube showed that all bodies which fluoresce with the X-rays 

 present the same phenomenon with the Becquerel rays. The 

 division proved to be somewhat arbitrary, no general relation 

 between the position of a salt and its chemical composition 

 being apparent. — On the hydrated peroxides of barium, 

 by M. de Forcrand. A calorimetric study of the 

 action of solutions of hydrogen peroxide upon baryta. — 

 On the separation of the rare earths, by M. R. Chavastilon. 

 In the separation of thorium and cerium from lanthanum and 

 didymium, the author reverses the method of M. Urbain and 

 keeps the thorium in solution. Two methods are proposed ; in 

 the first the solution of the rare earths is poured into an excess 

 of neutral sodium sulphite, the cerium, lanthanum and didy- 

 mium being precipitated as .sulphites, the thorium remaining in 

 solution. In the second method, the solution of the rare earths 

 is precipitated by adding ammonia and hydrogen peroxide, from 

 which precipitate alkaline bicarbonates extract the thorium 

 and ceriux oxides only.— Chemical reactions produced in a 

 solution ; vapour tension of the solvent, by M. A. Ponsot. A 

 mathematical discussion of the conditions under which the 

 vapour pressure of a liquid increases, when reactions occur 

 between substances dissolved in it.— On the detection, esti- 

 mation and variations in cystine in polluted water, by M. H. 

 Causse. The reagent used is the chloro-mercurate of sodium 

 /-diazobenzenesulphonate, which produces with cystine ayellow- 

 orange coloration, the depth of which is proportional to the 

 quantity of cystine present. The author has been able to trace 

 a direct connection between the presence of cystine in a drinking 

 water and an outbreak of typhoid fever. — On certain phenomena 

 presented by nuclei under the action of cold, by MM. L, 



