350 



NATURE 



[May 12, 1921 



Societies and Academies. 

 London. 

 Royal Society, May 5. — Prof. C. S. Sherrington, 

 president, in the chair. — Dr. H. Head : Release of 

 function in the nervous system (Croonian lecture). 

 Hughlings Jackson's law that destructive lesions do 

 not cause positive effects, but induce a negative condi- 

 tion, which permits positive symptoms to appear. 

 Control of higher over lower centres. Structural 

 lesions may remove this dominance and so reveal the 

 activity of subordinate centres; this is "disintegra- 

 tion " of function. Should the stimulus become ab- 

 normally intense or central resistance be weakened, 

 forms of reaction may break through which are 

 normally suppressed; this is "escape frorn control." 



Physical Society, March 22. — Prof. W. Eccles, vice- 

 president, in the chair. — W. N. Bond : The effect of 

 viscosity on orifice flows. Determinations were made 

 of the coefficient of discharge through an orifice 

 01469 cm. in diameter of solutions of glycerine and 

 water, varying in kinematic viscosity from 001 to 7. 

 The results are plotted in a manner which combines 

 both purely viscous and purely turbulent flows in one 

 graph. The effect of slight viscosity is to increase the 

 coefficient of discharge. — Dr. A. GriflBths and Con- 

 stance H. Griffitlis : Viscosity of water and low rates 

 of shear. The determination of the coefficient of 

 viscosity of water by a method in which water is 

 forced along glass capillary tubes of 15 to 2-0 mm. 

 bore at rates of flow varying from i litre in two years 

 to I litre in t\yenty-four years. The liquid fills a 

 closed tubular circuit which for purposes of description 

 may be said to be rectangular in shape, two of the 

 tubes being horizontal and two vertical. The circula- 

 tion is caused by a difference of density obtained by 

 having a weak solution of uranine in one vertical tube 

 and pure water in the other. Values for the coefficient 

 of viscosity are given. There is no experimental evi- 

 dence that at the extremely low rates of shear the 

 viscosity of air-free water in glass capillary tubes 

 differs from its value at normal rates of shear. — B. S. 

 Smitli and G. F. Partridge : A methqd of measuring 

 frequencies. A heterodyne method of measuring 

 frequency by comparison with a calibrated valve oscil- 

 lator. Calibration is performed by means of two valve 

 oscillators capable of g^ivini? frequencies of looo/sec. 

 upwards. The frequency of the oscillations is raised 

 alternately to give a beat note the pitch of which is 

 determined by comparison with a fork. Intermediate 

 frequencies are found by interpolation on the calibra- 

 tion curve. For the measurement of acoustic fre- 

 quencies the sounds are converted into alternating 

 currents by a suitable transmitter. 



Geological Society, April 20.— Mr. R. D. Oldham, 

 president, in the chair. — J. A. Douglas : Geological 

 sections through the Andes of Peru and Bolivia. 

 III. : From Callao to the River Perene. The zone 

 of Mesozoic rocks extends to the Pacific coast, which 

 is here formed of shallow-water deposits of Lower 

 Cretaceous age. The granodioritic batholite. which 

 forms the core of the Andes is encountered in the 

 neighbourhood of Lima, and again near the summit 

 of the range. The western flanks of the Cordillera 

 are characterised by a great development of Cretaceous 

 porphyritic agglomerate; while the normal cal- 

 careous facies is the dominant feature of the high- 

 level regions. The intensity of the Tertiary folding 

 has obscured the effects of the post-Jurassic uplift 

 previously shown to occur in the south, and it is only 

 on palaeontological evidence that a break in the 

 sequence of Mesozoic deposits can be determined. 

 The rocks of Palaeozoic aspect which form the eastern 



NO. 2689, VOL. 107] 



flanks of the Cordillera are mostly unfossiliferous, and 

 have largely been converted into phyllites and mica- 

 schists, penetrated by granite. On the Rio Perene a 

 bigger mass of red granite is found, which is essen- 

 tially a rock of "alkaline" character. It is sug- 

 gested that its origin is antecedent to the uplift of 

 the mountain ranges. — Prof. O. T. Jones : The Valen- 

 tian series. The history of the nomenclature from 

 the time of Murchison onwards was traced and the 

 relation of the Tarannon to the Llandovery and the 

 Birkhill-Gala rocks discussed in detail. In view of 

 the occurrence of two distinct facies (graptolitic and 

 shelly) of the Valentian rocks, two separate classifica- 

 tions are in use. The succession of graptolites is 

 made the basis of one of these, the series being divided 

 into a Lower or Birkhill stage and an Upper or Gala 

 stage, each of which is further divided into sub- 

 stages and zones. The mixed facies of Girvan allows 

 certain shelly horizons to be brought into relation 

 with the graptolitic scale. The fauna of various dis- 

 tricts where the shelly facies prevails is compared 

 with the Girvan succession and a general correlation- 

 table of the Valentian rocks proposed, the rocks of 

 the shelly facies being divided into two stages — Lower 

 and Upper Llandovery. The base-line of the Valen- 

 tian series was discussed, and in most districts evi- 

 dence is found of an abrupt lithological change at a 

 certain horizon, which in some cases amounts to a 

 palaeontological break. The phenomena at that 

 horizon suggest arrested sedimentation, if not also 

 actual erosion. 



Paris. 



Academy of Sciences, April 18. — M. Georges Lemoine 

 in the chair. — J. Boussinesq : The flattening along the 

 polar axis, by surface tension, of a liquid drop, of 

 revolution and without weight, possessing a given 

 angular velocity w of rotation round this axis. — E. 

 Bourquelot and xM. Bridel : The application of the bio- 

 chemical method of research on glucose to the study 

 of the products of fermentation hydrolysis of inulin. 

 By the hydrolysis of inulin by the inulase from Asper- 

 gillus niger reducing products are obtained which pos- 

 sess the rotary power of d-fructose, and do not 

 combine with methyl alcohol under the influence of 

 emulsin. It is concluded that the hydrolytic fer- 

 mentation of inulin gives no glucose. — L. Cuenot : 

 Regeneration of claws in the place of antennae re- 

 moved by cutting in a Phasmid. — B. Gambler : Non- 

 unicursal algebraic curves with constant torsion. — L. 

 Montangerand : Observation of the eclipse of the 

 sun on April 7, made at Toulouse Observatory.— A. 

 Veronnet : The constitution and formation of the spiral 

 nebulae. A mathematical investigation of the condi- 

 tions under which a double star formed of tvvo com- 

 ponents of large, homogeneous, and approximately 

 equal masses may lead to the formation of a spiral 

 nebula. — H. Chipa'rt : The homologues of a permanent 

 uniformly magnetised magnet. The law of the 

 ellipsoid.— L. and E. Bloch : The spark spectra of 

 gold and platinum in the extreme ultra-violet. Tables 

 of wave-lengths of the lines of the spark spectra of 

 these two metals are given between the limits 1843 

 and 1402. — A. Portevin : The use of very slow cooling 

 for the micrographical study of alloys and the struc- 

 ture of the tungsten steels. The advantages of the 

 very slow cooling are that the structure of the alloys 

 appears on a larger scale, permitting projection on 

 the screen with relatively low magnification, and 

 sometimes new, unsuspected equilibrium structures 

 are shown The case of tungsten steels is considered 

 in detail, and two photomicrographs of these alloys 

 are reproduced. — M. Francois : A microscopic arrange- 

 ment for the examination of opaque crystals. — G. 

 Dubreuil : The principle of a new method of graphical 



