52 NATURE 
[Marcu 14, 1912 
amount that entered it was ascertained that 7°79 per 
cent. of the tube’s capacity had leaked through the 
devitrified silica.—Sir William Crookes: The volatility 
of metals of the platinum group.—Prof. W. M. 
Hicks: A critical study of spectral series. Part ii.— 
The principal and sharp sequences and the atomic 
volume term. This is a sequel to a paper on the 
same subject published in the Philosophical Trans- 
actions, vol. ccx. (1910). The sequences which give 
the principal and the sharp series are discussed as 
they occur in the second and third groups of the 
periodic table of the elements, and it is found that, 
in opposition to the rule in the alkalies, the P-series 
is based on the s-sequence and the S-series on the 
p-sequence. Additional evidence is afforded to show 
that these sequences depend on atomic volumes of 
elements in quite definite way.—Prof. W. E. 
Dalby: An optical load-extension indicator, together 
with some diagrams obtained therewith. The paper 
describes a new instrument by means of which auto- 
matic records of load-extension diagrams can be 
obtained with precision, the records being free from 
errors due to inertia, pencil-friction, and to any strains 
caused by the yielding of the testing machine in 
which the specimen is being tested.—R. Whiddington : 
The transmission of kathode rays through matter. 
It has been found experimentally that a kathode ray 
moving with velocity v, can possess, after traversing 
a thickness x of material, a velocity v, given by the 
relation v,*—v,*=ax, where a is a constant depend- 
ing on the nature of the material—R. Whiddington : 
The velocity of the secondary kathode particles ejected 
by the characteristic Réntgen rays. Application of 
the results of the preceding paper to the experimental 
investigations of Beatty into the absorption of kathode 
particles in air leads to the conclusion that the fastest 
of the secondary kathode particles ejected from a plate 
by Réntgen rays characteristic of the element of 
atomic weight w possess a speed equal to k'w, where 
k’ is a constant nearly equal to 10o8.—E. E. Fournier 
d’Albe : The potential effect in selenium. A new type 
of selenium bridge (or “selenium cell”) was con- 
structed by coating a plate of unglazed porcelain of 
high insulating power with graphite and dividing the 
surface into two conducting portions by cutting, with 
a diamond, a to-and-fro line through the graphite. 
The plate was then coated with selenium and sensi- 
tised. The bridges so constructed showed no 
polarisation, and were well adapted to the study of 
the “potential effect,’ or the change of resistance 
with the voltage applied. 
Institution of Mining and Metallurgy, February 15.— 
Mr. H. Livingstone Sulman, president, in the chair.— 
C. O. Bannister: On the theory of blast-roasting of 
galena. This is an exhaustive record of researches 
made by the author, with the view of determining the 
nature of the reactions that take place during the 
blast-roasting of galena when present alone and when 
in admixture with lime, limestone, gypsum, etc. The 
introduction of the paper deals with the previous re- 
searches of Huntington and Heberlein, Carmichael 
and Bradford, Savelsburg, Austin, Dwight and Lloyd, 
and others, and the theories to which the published 
results of those authorities gave rise, and the author 
then goes on to describe his own recent series of 
experiments, with diagrams and tables showing the 
observed conditions in temperature at different periods 
of time during the course of roasting galena mixed 
with lime, silica, litharge and lime, limestone, cal- 
cium sulphate, magnesium oxide, ferric oxide, slaked 
lime, ete. As a result of his carefully conducted ex- 
periments the author has arrived at the conclusion 
that the older theories as to the formation and subse- 
quent reaction of peroxides, plumbites, and plumbates 
NO. 2211, VOL. 89| 
are wrong, as also those depending on definite re- 
actions between calcium sulphate and lead sulphide; 
that later theories depending on the diluent effect of 
various agents are only partially true; that the oxida- 
tion of lead sulphide tales place in three stages; that 
in the presence of lime, limestone, and magnesia, the 
sulphates of calcium or magnesium are formed in 
preference to sulphate of lead; that silica and calcium 
act merely as diluents, without chemical action until 
a temperature of over 1000° is reached; that ferric 
oxide in certain physical states acts as a catalysing 
agent; and that silica acts at high temperature in 
decomposing lead sulphate and calcium sulphate.— 
H. K. Picard: A graphic method of illustrating the 
results of extraction tests. The author has devised 
for his own use.a system of placing in graphic form 
the results of extraction or concentration. tests on ore 
samples, which is illustrated and described. It con- 
sists in the employment of ‘‘ squared” paper, on 
which areas are marked out for the various weight 
units of the tests carried out, and the percentages of 
ore content are indicated by covering so many squares 
of these areas with a wash of solid colour. The re- 
sult, as shown in an example submitted by the 
author, is at once apparent, and from the graphic in- 
dications it can be ascertained whether certain pro- 
ducts should be rejected, re-treated, or mixed with 
other products.—A. T, French: Quick combination 
methods in smelter assays. This paper, which is 
practically a collection of laboratory notes presenting 
together a scheme for the combination of various 
approved methods of smelter analysis, was not dis- 
cussed at the meeting owing to the lateness of the 
hour. 
Geological Society, February 28.—Dr. Aubrey 
Strahan, F.R.S., president, in the chair.—L. J. 
Wills: Late Glacial and post-Glacial changes in the 
Lower Dee Valley.—E. B. Bailey and M. Macgregor : 
The Glen Orchy anticline (Argyllshire). The district 
described stretches from the head of Loch Awe to 
Beinn Achallader, and is the south-eastern continua- 
tion of the Fort William, Ballachulish, and Appin 
country dealt with by one of the authors two years 
ago. The subject is the tectonics of the schists. 
CAMBRIDGE. 
Philosophical Society, February 26.—Dr. A. E&. 
Shipley, F.R.S., in the chair.—L. Doncaster: The 
chromosomes in oogenesis and spermatogenesis of 
Pieris brassicae.—R. P. Gregory: The chromosomes 
of a giant form of Prumula sinensis.—Dr. Cobbett ; 
Preliminary note on the occurrence of living bacteria 
in the organs and blood of normal animals.—S. R. 
Price : Some observations with dark-ground illumina- 
tion on plant cells —R. C. McLean: Rhizopods from 
the Carboniferous period. 
EDINBURGH. 
Royal Society, February 5.—Sir T. R. Fraser, 
F.R.S., vice-president, in the chair.—Dr. R. Stewart 
MacDougall: The bionomics of Nematus ericksoni 
(Hartig), the large larch-sawfly. The larve of this 
sawfly, which was first noticed in numbers some 
years ago in the Lake district, have also been found 
at work in Wales, and more recently in Perthshire 
and Forfarshire. In breeding out adults from cocoons 
collected in spring, Dr. MacDougall obtained 165 
females to one male. Hewitt had previously recorded 
two males to 298 females. To test this suggested 
parthenogenesis, seven newly issued virgin females 
were placed on May 26, 1910, on a young larch, which 
was potted and so confined that no other insect had 
access to it. By June 12 three were dead, and in a 
few. days the remaining four had died. Although 
: there was no reasonable doubt as to the sex, the dead 
