494 
NATURE 
[JULY 1D, 1612 
rium are described.—Karl Pearson: The intensity of 
natural selection in man. The following statement 
has recently received much currency :—A high infant 
death-rate in a given community implies in general 
a high death-rate in the next four years of life, while 
low death-rates at both age-periods are similarly 
associated. The evidence in support of the statement 
is not valid; it consists solely in showing that a bad 
environment raises both infant and child death-rates. 
The statement is not true even when no correction 
is made for differential environment. ‘The question o} 
a selective death-rate is the question of whether natural 
seleetion—Darwinism—applies to man. The present 
paper does not determine how far a rising infant 
death-rate is really the cause of a falling child death- 
rate, but its aim is to show that there is no such 
general rule as that stated to hold. If that rule were 
a demonstrable truth, then we might confidently assert 
that Darwinism did not apply to civilised man. As 
a matter of fact, others methods of inquiry indicate 
that at least 60 to 70 per cent. of the deaths in civilised 
human communities are selective, i.e. due to the 
elimination of those with inferior constitutional powers 
of resistance.—Dr. T. M. Lowry: Optical rotatory 
dispersion. Part i. 
tory dispersion in quartz of light in the visible region 
of the spectrum.—J. J. Manley: The apparent change 
in mass during chemical reaction.—Dr. W. H. Eccles ; 
The diurnal variations of the electric waves occurring 
in nature, and on the propagation of electric waves 
round the bend of the earth. The natural electric 
wave train radiating from a lightning discharge pro- 
duces, it is well known, a disturbance in apparatus 
for the reception of wireless telegraph messages. 
Normally these disturbances form a steady stream of 
faint or loud clicks in the receiving telephones. The 
rate at which they are received at a station varies 
from hour to hour during the twenty-four hours, and 
also with the season, but as a general rule the dis- 
turbances—or “‘strays"’ as they are often called—heard 
at night are stronger and more frequent than those 
heard in the day. The change from day to night and 
from night to day conditions is very noticeable at 
sunrise and sunset. It is chiefly this transition period 
that is investigated in the present communication. In 
order to explain the phenomena the author develops 
a hypothesis which is based on a proposition to the 
effect that the velocity of electric waves through 
ionised air increases with increasing ionisation.—Rev. 
A. L. Cortie: Report on the total solar eclipse of 1911, 
April 28. Communicated by the Joint Permanent 
Eclipse Committee.—W. Hamilton Wilson : An experi- 
mental investigation of the influence of the condenser 
on the working of a Ruhmkorff coil, together with a 
practical outcome thereof.—Prof. D. Fraser Harris and 
Dr. H. J. M. Creighton: Studies on the reductase of 
liver and kidney. Part ii—Prof. M. W. Travers and 
Ramu Chandra Ray: Borohydrates. Part i.—Prof. 
G. N. Stewart: The specific conductivity of solutions 
of oxyhzmoglobin. lo MWe Gifford: The existing 
limits of uniformity in producing optical glass.—Prof. 
A. C. Seward: A petrified Williamsonia from Scotland. 
—Prof. A. W. Porter and Dr. F. W. Edridge Green : 
Negative after-images and successive contrast with 
pure spectral colours. A definite portion of the retina 
was fatigued by steadily gazing at an isolated region 
included between two definite wave-lengths in the 
Edridge green colour perception spectrometer. After 
the fatiguing light had been viewed for a period of | 
about 20 seconds, the eye was turned to a screen on 
which a spectrum was situated, so that the after- 
image formed a band running right across the spec- 
trum on the screen and occupying its centre. Experi- 
ments were also made with the spectrum replaced by 
monochromatic bands, and on the appearance of the 
NO. 2228, vor. 89] 
The natural and magnetic rota- | 
| relation between capillary pressure and secretion. 
_J. G. Wilson and F. 
sodium flame after fatigue to various colours. It is 
held that the facts described cannot be explained on 
either the Hering or Young-Helmholt theories. The 
explanation on the Edridge-Green theory of cotour- 
vision is the same as that given for other facts of 
simultaneous contrast (Proc. Roy. Soc., B, vol. Ixxxiv., 
1912, p. 546).—Leonard Hill and M. Flack: The 
i ll. 
The secretion of the aqueous and the intra-ocular 
pressure.—Prof. W. B. Bottomley: Some conditious 
influencing nitrogen fixation by aerobic organisms.— 
H. Pike: The effects of stimula- 
tion and extirpation of the semicircular canals of the 
ear and their relation to the motor system.—W. 
Wilson : The absorption and reflection of homogeneous 
particles.—Prof. H. M. Macdonald: The effect of an 
obstacle on a train of electric waves.—Dr. Walter 
Wahl: Optical investigations of crystallised nitrogen, 
argon, methane, and some of the simpler organic 
compounds of low melting points. A quartz glass 
vessel, holding a very thin layer (0°05 mm.) of sub- 
stance between polished quartz glass plates, has been 
constructed. In this vessel N, A, CH,, &c., have 
been crystallised and investigated crystal-optically :— 
(1) Nitrogen crystallises in the regular system; (2) 
argon is ‘regular ; (3) methane is regular; (4) ethyl- 
ether is rhombic. Ethyl alcohol, acetone, methyl 
alcohol, and carbon bisulphide are monoclinic or tri- 
clinic. Methylalcohol occurs in two polymorphic 
forms, changing reversibly into each other.—Sir 
W. de W. Abney: Colour-blindness and the tri- 
chromatic theory. Part iv. Incomplete colour-blind- 
ness. In this communication the author shows how a 
simple test is capable of giving a quantitative measure 
of the degree of colour-blindness which a colour-blind 
person possesses. By matching a single colour of 
the spectrum with the colour of the ‘lig sht coming 
from such a solution as of chromate of potash the 
degree of colour-blindness can be immediately deter- 
mined. Further, he gives a method by which any 
displacement of the green or red sensation curves can 
be measured with great accuracy.—Prof. W. H. 
Young: The multiplication of successions of Fourier 
constants.—C. E. Haselfoot : The diffusion of ions into 
gases at low pressure.—Prof. J. S. Townsend and 
T. T. Tizard ; Effect of a magnetic force on the motion 
of negative ions in a gas. 
Dustin. 
Royal Dublin Society, May 21.—Mr. R. LI. Praeger 
in the chair.—Prof. G. H. Carpenter: Injurious in- 
sects and other animals observed in Ireland during 
the year 1911. Among the insects mentioned are the 
Diptera, Trichocera fuscata (injurious to swedes) and 
the narcissus-fly (Merodon equestris), the larvee of both 
being described. There are records of several saw- 
flies, including Fenusa pumilio on raspberry, and 
Nematus Prciisonii on larch. Slugs (Arion and Agrio- 
limax) have been observed eating the bark of the 
Weymouth pine. 
June 25 R. Li. Praeger in the chair.—J. 
Dowling : Steady and turbulent motion in gases. eee 
lowing Osborne Reynolds’s well-known work on the 
flow of water through tubes, the author extends the 
investigation to gases, and verifies Revnolds’s formula 
for the critical velocity at which turbulence sets in, 
VizeVie= Kn 
pit 
and p the density). Different gases are experimented 
with, and the effects of temperature examined. A 
new type of critical velocity is also found to exist, and 
is discussed. This second critical velocity is found to 
A g - Nee Koa 
vary according to the equation (V.—4')=— - 
(where a is the tube radius, 7 the viscosity, 
(where 
K’ and k’ are new constants). An ionisation method ts 
