Marcu 24, 1923] 
NATURE 
419 

That from Pelidnota sumptuosa shows a central 
maximum bordered on either side by subordinate 
maxima in exactly the way that reflection from a 
uniformly spaced assemblage of 34 thin plates would 
uire. In the spectrum from one of the golden 
beetles, Callodes parvulus, the bands are accounted 
for on the supposition of two assemblages, each 
consisting of several reflecting planes, the distance 
between the assemblages being about 84.—J. W. 
Nicholson: Oblate spheroidal harmonics and their 
applications.—J. W. Nicholson and F. J. Cheshire: 
On the theory and testing of right-angled prisms.— 
J. C. McLennan and D. S. Ainslie: On the fluores- 
cence and channelled absorption spectra of caesium 
and other alkali elements. Caesium exhibits a 
fluorescence and a channelled absorption spectrum in 
the neighbourhood of A\=8000 when the vapour of 
he element is traversed by white light. In the 
absorption spectrum, bands separated by intervals 
at were simple multiples of 24 were found. 
ike sodium, potassium exhibits channellings in its 
absorption spectrum, in the neighbourhood of the 
second member of its doublet series. Indications 
have been obtained of channelling in the absorption 
spectrum of lithium in the near ultra-violet region.— 
. Stiles: The indicator method for the determina- 
tion of coefficients of diffusion in gels, with special 
eference to the diffusion of chlorides. The coefiicient 
of diffusion increases at a greater rate per degree rise 
temperature the higher the temperature; the 
elation between coefficient of diffusion and tempera- 
re in gels is thus not linear as is usually assumed 
‘or free diffusion in water. The coefficient of diffusion 
decreases with increasing concentration of gel and 
increases with decreasing concentration of the diffus- 
mg salt. Empirical expressions are given for these 
elationships.—H. T. Flint: A generalised vector 
nalysis of four dimensions. An account is given of 
invariant vector calculus in a notation which is 
he natural generalisation of that of Gibbs. Contra- 
variant and covariant vectors are related by means 
of an operator—the extended idem-factor, and 
tensors are introduced as dyadics and polyadics. 
The expressions familiar in the tensor calculus of 
iemann and Christoffel appear very simply in the 
analysis. Separated points are connected by the 
veodetics, and a simple-definition of parallelism at 
wo points leads at once to the Weyl parallel dis- 
placement relations. 








































Geological Society, February 28.—Prof. A. C. 
Seward, president, and, afterwards, Prof. W. W. 
Watts, vice-president, in the chair.—S. Hazzledine 
Varren: (1) The late glacial stage of the Lea Valley 
Third Report). One new section found occurred at 
he level of, and in the area occupied by, the Middle 
Taplow Terrace, whereas all the other sections 
vere in the Low Terrace. It consisted of a bed of 
eed-bearing clay, in the middle of an old gravel-pit 
ly built over. The Taplow deposits yield a 
airly temperate fauna and flora. The site is close 
to the head of a small streamlet, and it is assumed 
that the Arctic plant-bed is of Low-Terrace or 
Ponders-End date, and that it represents the silting 
of a stream which flowed across the Taplow Terrace. 
cecording to a report on the Arctic flora by Mrs. E. 
M. Reid and Miss M. E. J. Chandler, there is nothing 
to distinguish the flora from that of the previously- 
scribed localities of the Lea Valley. (2) The 
I “ge i ae bed of Clacton-on-Sea (Essex), and 
s flora and fauna. The deposit fills a deep, narrow, 
steep-sided, river-channel which apparently flowed 
nto the Thames when that river occupied the deep 
hannel now submerged off the coast of Essex. The 
lacton bed yields evidence of an abundant flint- 
NO. 2786, VOL. 111] 
industry which is one of the best-known representa- 
tives of the Mesvinian series. This is of Late Chellean 
or Early Acheulean date, although it shows no 
cultural connexion with those industries, but it may 
be the precursor of Mousterian. The deposit is also 
rich in mammalian remains. Appended to the paper 
are detailed reports on the paleontology. 
Linnean Society, March 1.—Dr. A. Smith Woodward, 
president, in the chair.—J. N. Halbert: Notes on 
the Acari, with descriptions of new species.—C. F. M. 
Swynnerton: Aspects of African woodland formations. 
Rain-forest, coppice, and thicket due to grass-fires, 
the means of prevention from injury by such fires, 
and the preservation of the forests by careful nurture, 
were dealt with, 
Aristotelian Society, March 5.—Prof. A. N. White- 
head, president, in the chair.—E. S. Russell: Psycho- 
biology. Physico-chemical method is applicable to 
many of the phenomena of life, but it fails of complete 
success because it cannot take account of the in- 
dividuality and striving of the living thing, nor its 
flexibility of response. Also it cannot take into 
consideration, as an active factor, the past history 
of the organism, for it must regard past history as 
completely summed up in present state. The true 
alternative to the materialistic view is not vitalism, 
but a psychobiological view based upon a monadistic 
philosophy. Both the movements and the morpho- 
genetic responses of the organism must on this view 
be interpreted as actions of a living individuality, 
carried out in response to its own sensed environment, 
in pursuance of the fundamental conative impulses 
which are the core of its being. 
Zoological Society, March 6.—Sir S. F. Harmer, 
vice-president, in the chair—Mr. Caldwell: A case 
of apparent melanism in Tippelskirch’s Giraffe 
(Givaffa camelopardalis tippelskircht)—H. G. Cannon : 
A note on the zoza of the land-crab, Cardisoma 
armatum.—Miss L. E. Cheesman: Notes on the 
ae of the land-crab, Cardisoma armatum.— 
.. F. Sonntag: The comparative anatomy of the 
tongues of the mammalia.—VIII. Carnivora.—T. H. 
Ring: The elephant-seals of Kerguelen Land.—R. 
Kirkpatrick : On the tunicate Rhizomolgula globularis 
Pallas. No. 24. Results of the Oxford University 
Expedition to Spitsbergen, 1921. 
Society of Public Analysts, March 7.—Mr. P. A. 
Ellis Richards, president, in the chair.—A,. Lucas: 
The examination of firearms and projectiles. A 
particular weapon may sometimes be recognised by 
the rifling marks imprinted on a bullet, while the 
nature of the fouling left in the barrel after the 
weapon has been fired may afford information as to 
the nature of the original powder and also, in some 
cases, the period that has elapsed since the last 
discharge. The composition, dimensions, and mark- 
ings on bullets, slugs, etc., are described, and direc- 
tions are given for the reproduction of rifling marks 
and for the chemical analysis of projectiles.—R. C. 
Frederick : The interpretation of the results obtained 
in the analysis of potable waters.—S. B. Phillips: 
Determination of the purity of vanillin. After 
reviewing the various methods proposed from time 
to time the author described two processes for 
estimating vanillin—one volumetric, and the other 
gravimetric. 
EDINBURGH. 
Royal Society, March 5.—Prof. F. O. Bower, 
president, in the chair—F. O. Bower: The relation 
of size to the elaboration of form and structure of 
