April 24, 1919] 



NATURE 



59 



adequate training of efficiently educated youths as 

 leaders in our chief industries and what number 

 avail themselves of such training. Certainly it would 

 be found far below that of Germany or the United 

 States, our chief industrial competitors. Inquiry 

 should also be made as to the disposition of our chief 

 j technical institutions, especiallv those equipped for 



the efficient training of day students, and as to the 

 desirability of the official recognition of such institu- 

 tions as specialise in the science and technology of 

 certain industries, e.g. iron and steel at Sheffield; 

 cotton textiles and chemical products, particularly 

 dyes, at Manchester; the leather industry at Leeds'; 

 shipbuilding at Glasgow, Newcastle, and Belfast; 

 mining at Wigan, Newcastle, and Cardiff; textiles 

 other than cotton at Leeds, Huddersfield, and Brad- 

 ford ; mechanical and electrical engineering at various 

 chief centres, etc. There is reason to believe that 

 public opinion is ripe for much larger support both 

 from local and State funds. The new Education Act 

 will certainly add largely to the number of capable 

 students who will need the help of maintenance 

 scholarships, which should, in consequence, be very 

 largely increased, so as to enable them to proceed to 

 higher institutions for whole-time study. It is to be 

 hoped that this important memorandum will be cir- 

 culated to every Member of Parliament and to all the 

 education authorities and chief industrial associations 

 throughout the kingdom. 



SOCIETIES AND ACADEMIES. 

 London. 

 Optical Society, April lo.— J. W. French: The un- 

 aided eye. After a brief historical introduction, the 

 principal dioptric features of the eye were considered, 

 particularly those relating to the pupil reflexes. By 

 means of a simple pupilometer the diameter of the 

 pupil when applied to optical instruments was 

 measured. The variations of the pupil with varying 

 illumination of the whole retina, of the macula lutea, 

 and of several zones of constant area were also 

 measured and the results discussed. It would appear 

 that for the macula lutea the pupil area varies as the 

 fifth root of the illumination. The zone around the 

 macula lutea is more sensitive, and the sensitiveness 

 diminishes thereafter towards the margin of the 

 retina. So far as the pupil reflexes are concerned, the 

 two eyes are quite independent of each other; while 

 the pupil area of the one eye under constant illumina- 

 tion remains constant, the other eye under simul- 

 taneous variation of the illumination varies in accord- 

 ance with the above law. The variation of the pupil 

 area with accommodation is quite! independent of the 

 illumination, and is determined bv the refractive 

 power of the crystalline lens. — T. Smith : The spacing 

 I if glass-working tools. In constructing optical 

 -\stems the exact curvatures for the surfaces deter- 

 mined by calculation need not be employed, but the 

 I'partures must lie between limits which will be 

 functions of the nominal curvatures. It follows that 

 a system of property spaced tools should suffice to 

 meet all normal requirements. The basis on which a 

 svstem should be constructed is discussed, and a pro- 

 posed standard list of tools is derived from an aberra- 

 tional condition, together with assumed extreme rela- 

 tions between aperture and focal lenf*th and between 

 anerture and radius of curvature. The total number 

 of tools, which is finite, occurs as an independent 

 variable in the formula on which the svstem is- con- 

 structed, and in the absence of experimental investiga- 

 tions this must be determined bv comparing the results 

 obtained from an arbitrarily assumed value with the 

 lists that manufacturers have found from experience 

 to be reasonablv spaced. A comparison between the 

 NO. 2582, VOL. TO3] 



list derived by assuming the total number of different 

 curvatures in the complete set to be one thousand and 

 the lists of two makers shows satisfactory agreement. 



Paris. 

 Academy of Sciences, March 31.— M. L^on Guignard 

 in the chair. — A. Lacroix : The leucitic lavas of 

 Trebizond and their transformations. From the data 

 furnished by chemical analyses it is impossible to 

 get an exact idea of the magmatic relations of these 

 rocks, since the essential ratios are disturbed by 

 chemical and mineralogical transformations of 

 secondary origin. — -G. Bigourdan : The observatory of 

 Le Monnier in the rue Saint-Honor^. Historical 

 account of Le Monnier's astronomical work and pub- 

 lications, and of his instruments. — Ch. Barrois and 

 P. Prnvost : The stratigraphical divisions of the Coal 

 Measures of the North of France. — H. Deuvilli : 

 Evolution and classification of Nummulites. — C. Richet 

 and H. Cardot : Sudden mutations in the formation 

 of a new race of micro-organisms. A study of the 

 modification produced by an arsenical medium upon 

 the production of lactic acid by a pure lactic organism. 

 This organism does not gradually become accustomed 

 to the poison, but the tolerance shows a series of 

 sudden variations, each of which is marked by intense 

 multiplication. — M. de Sparre : Conditions to be ful- 

 filled for increasing the flow, and hence the work, in 

 an hydraulic installation without modifying the pipe. 

 — G. A. Boulenger : An interesting case of sexual 

 dimorphism in an African snake, Bothrolyciis ater. — 

 M. Eugene Casserat was elected a non-resident 

 member in succession to the late M. H. Bazin. — P. 

 Sabatier and G. Gaudion.— Catalytic dehydrogenation 

 by nickel in presence of hydrogen. Pinene, limonene, 

 camphene, menthene, and cyclohexene carried by 

 hydrogen over nickel at 35o°-36o° C. undergo simul- 

 taneously hydrogenation and dehydrogenation. The 

 reaction has been applied to compounds containing 

 oxygen. Cyclohexanol gives phenol ; pulegone, a 

 mixture of cresol and thymol. — S. Lefschetz : The 

 analysis of algebraic varieties. — L. E. J. Brouwer : 

 The enumeration of regular Riemann surfaces of 

 Genus I. — A. Veronnet : The temperature of equili- 

 brium of a gaseous star for any rav. — A. Colson : The 

 theory of solubilitv.— C. ChineVeau' and R. Audnbert : 

 Absorption in turbid media. Dispersion by internal 

 diffusion! — P. Vaillant : The production of a con- 

 tinuous current by the application of an alternating 

 electromotive force to a voltameter with platinum 

 electrodes. — J. Martinet : The mobility of the hydrogen 

 atoms in organic molecules. The action of phenvl- 

 hydrazine on dioxindols. Although neither aldehydes 

 nor ketones, dioxindols give phenylhydrazones with 

 great ease. The preparation and properties of several 

 of these phenylhydrazones are described. — G. Guilbert : 

 Some examples of "cyclone compression." Cyclonic 

 centres sometimes present the phenomenon of dis- 

 appearing very rapidly, in twenty-four hours or even 

 less. This the author terms " c\Tlone compression," 

 and directs attention to several examples which have 

 occurred recently. — A. Jauffret : The determination of 

 the woods of two species of Dalbergia from Mada- 

 gascar, according to the characters of their colouring 

 matters. The colouring matters extracted from these 

 two species by solvents give different chemical re- 

 actions and absorption spectra. These characters are 

 constant for each soocies.- -L. Daniel : Researches on 

 the comparative development of the lettuce in sunlight 

 and in the shade. — H. Colin : The utilisation of 

 glucose and laevulose bv the higher plants. .Analyses 

 are given of total dextrose and Isevulose and the ratio 

 of these two hexoses in various parts of the plant in 

 tho cns«^ of beetroot. Jerusalem artichoke, and chicorv. 

 v.. Fsclangon : The physiological sensations of 



