26 



NATURE 



[July 7, 1923 



Societies and Academies. 



London. 



Royal Society, June 28. — V. H. Blackman, A. T. 

 Legg, and F. A. Gregory : The effect of a direct 

 electric current of vcr>' low intensity on the rate of 

 growth of the coleoptilc of barley. The coleoptile 

 {sheathed plumule or young stem) of barley seedlings 

 is exposed to an electric discharge from a point 

 charged positively to about 10,000 volts (crest value) 

 and placed at such a height above the coleoptile 

 that a current of 0-5 x lo"" amp. passes through it, 

 the current density being 4 x lo"* amp. per cm.** 

 Under these conditions the rate of growth is markedly 

 accelerated from the first hour onward, showing in 

 the third hour a percentage increase above that of 

 the control plants of 7-53 ± i -95. After the cessation 

 of the current a well-marked after-effect, greater 

 than the direct effect, is observed, the enhanced rate 

 of growth steadily continuing and showing a per- 

 centage increase of 15 -68 ±2-62 above that of the 

 controls. The after-effect is greater with a short 

 period of discharge of i hour than with a longer 

 period of 3 hours. When the point is negatively 

 charged the rate of growth is increased during the 

 first hour, but the increase becomes less with time. 

 An after-effect follows, but it is markedly less. The 

 gaseous products of the discharge and the " electric 

 wind " play little or no part in the stimulation of 

 growth observed. The current alone appears to be 

 of importance. — M. S. Pembrey, N. W. MacKeith, 

 W. R. Spurrell, E. C. Warner, and H. J. Westlake : 

 Observations on the adjustment of the human body 

 to muscular work. In the dyspnoea produced by 

 running there is a disturbance of the acid-base 

 equilibrium of the body ; the relief of " second 

 wind " is the result of adjustments effected chiefly 

 by the respiration, circulation, and excretion by the 

 kidneys and skin. The sense of discomfort during 

 dyspnoea is associated with increased pulmonary 

 ventilation, the sense of relief at the onset of second 

 wind with diminished ventilation. Oliguria, or 

 anuria, appears as a constant feature during running, 

 even after taking 560 c.c. of tea as a diuretic. It 

 leads to a temporary retention of acid, which helps 

 the body to get rid of carbon dioxide and obtain 

 oxygen ; the water spared is available for excretion 

 by the lungs and skin, and will produce by evaporation 

 greater cooling than it would if it were discharged 

 as urinary water. The suspension of the activity 

 jof the kidneys appears to be due to an outflow of 

 constrictor impulses to the renal vessels. — Miss R. M. 

 Tupper- Carey and J. H. Priestley : The composition 

 of the cell wall at the apical meristem of stem and 

 root. The walls of the apical meristem of stem and 

 root differ in the ease with which cellulose may be 

 detected in them with iodine reagents. Macro- and 

 micro-chemical experiments show that the cellulose 

 in the wall of the root meristem is masked by its 

 combination with other substances, particularly 

 proteins and fatty acids. In the shoot meristem, 

 the cellulose is closely linked with larger quantities 

 of pectin, but less protein and fatty acid are present, 

 especially when the shoot is growing in the light. 

 — L. J. Harris : The titration of amino- and carboxyl- 

 groups in amino-acids, polypeptides, etc. — F. A. E. 

 Crew : Studies in intersexuality. II. Sex-reversal 

 in the fowl. — W. Finkler : Analytical studies on the 

 factors causing the sexual display in the mountain 

 newt {Triton alpestris). — G. A. Schott : On the 

 scattering of X- and 7-rays by rings of electrons. 

 The effect of damping of the incident radiation. 

 Damping of the usual type, of an amount compatible 

 with the production of moderately sharp lines in 



NO. 2801, VOL. I 12] 



the X-ray spectrum, increases slightly the total 

 scattering of short waves, such as the hard -y-rays, 

 although it decreases slightly that of long waves. 

 A single electron ring, such as is postulated in hydrogen 

 and ionised helium on Bohr's theory, is completely 

 unaffected by this type of damping. It seems 

 scarcely possible that damping can diminish the 

 total scattering for any type of atom below the 

 amount required by the simple pulse theory. — P. A, 

 MacMahon : On a class of transcendents of which 

 the Bcssel functions are a particular case. — L. C. 

 Martin : The photometric matching field. Improve- 

 ment in the visibility of faint contrasts observed 

 with central vision can be obtained by stimulating 

 the peripheral regions of the retina. An increase in 

 precision of the order of 30 per cent, is obtained in 

 photometric matches by surrounding the photometric 

 field with a larger area of approximately equal 

 brightness. — G. P. Thomson : Test of a theory of 

 radiation. Experiments with positive rays show that 

 visual and photographic effects can be obtained with 

 trains of waves shorter than those produced in the 

 emission of a quantum of light. — A. LI. Hughes and 

 P. Lowe : Intensities in the helium spectrum. The 

 curve showing the intensity of any spectrum Une 

 as a function of the energy of impact of the electrons 

 is characteristic of the series to which it belongs. 

 The intensities in the doublet system all decrease 

 rapidly as the energy of impact is increased from 

 34 volts. The principal series, iS - wP, of the singlet 

 system is characterised by a very great increase in 

 intensity as the energy of impact is increased from 

 34 volts up to about 80 volts, beyond which there 

 is little change. The lines of the diffuse series, 

 iP-wD, all show a maximum at about 75 volts. 

 The lines of the sharp series, iP - mS, after a small 

 initial rise to 60 volts, decrease slightly. — A. A. Dee : 

 The effect of quenching from above the carbide 

 transition temperature upon the magnetism of steel. 

 The magnetism of steel at ordinary temperatures is 

 not materially altered by quenching from above the 

 transition temperature of iron carbide, and therefore 

 the return of the carbide to the ferromagnetic state 

 is not retarded by sudden cooling from above the 

 transition temperature. — T. S. P. Strangeways and 

 H. E. H. Oakley : The immediate changes observed 

 in tissue cells after exposure to soft X-rays while 

 growing in vitro. Exposures for gradually increasing 

 periods, varying from 5 minutes to 2 hours, were 

 used. There is a latent period of about 15 to 20 

 minutes before the changes produced in the cells 

 by irradiation can be recognised. After 5 minutes 

 irradiation development of new dividing cells is 

 lessened. After exposure of 20 minutes or longer 

 the formation of new dividing cells practically 

 ceases. After exposure of 5 minutes granular changes 

 and fragmentation of the chromosomes occurs in 

 some cells in mitosis at metaphase and anaphase. 

 After exposure of 23 minutes or longer some cells 

 in mitosis show clumping of the chromosomes at 

 metaphase. As the time of exposure increases there is 

 increase in size and alteration in structure of the cyto- 

 plasm, nucleus, and nucleolus of some fully formed 

 cells. After an exposure of 60 minutes, affected cells 

 become disorganised, and eventually cytoplasm and 

 nucleus break up and appear to go into solution in 

 the surrounding medium. — W. B. Hardy and Ida 

 Doubleday : Boundary lubrication : the latent period 

 and mixtures of two lubricants. — C. T. R. Wilson : 

 Investigations on X-rays and jS-rays by the cloud 

 method. Pt. I. — X-rays. The tracks of the electron 

 ejected from the atom' which emits the quantum of 

 radiation and that of the electron ejected from the 

 atom which absorbs the radiation can be identified. 



