478 
NATURE 
[Marcu 17, 1904 
Geological Society, February 19.—Annual general meet- 
ing.—Sir Archibald Geikie, F.R.S., vice-president, in the 
chair.—After the presentation of the annual awards, the 
chairman proceeded to read the anniversary address that 
he had prepared, giving first of all obituary notices of 
several fellows deceased since the last annual meeting. He 
then dealt with the bearing of the evidence furnished by 
the British Isles as to the problem whether in the so-called 
secular elevation and subsidence of land it is the land or 
the sea which moves. ‘The conclusion thus reached was in 
favour of the generally accepted view that changes of level, 
such as those of Pleistocene and post-Pleistocene time, in 
the British area, have been primarily due, not to any oscilla- 
tion of the surface of the ocean, but directly to movements 
of the terrestrial crust. 
February 24.—Dr. J. E. Marr, F.R.S 
chair.—Eocene and later formations surrounding the 
Dardanelles: Lieut.-Colonel T. Engtish, late R.E. Our 
present knowledge of the older rocks, upon which the 
Tertiary beds surrounding the Dardanelles rest, only suffices 
to indicate the positions of the outcrops of a succession of 
schists, crystalline limestones, granites, and serpentines, 
which can be traced from the A%gean district into the 
Marmora, where they formed an archipelago in the Eocene 
Sea. The Eocene deposits surrounding these old rocks com- 
mence with sandstones, conglomerates, and clays, which 
become calcareous and nummulitic upward, and are about 
2000 feet thick in the aggregate. They are succeeded by 
3000 feet of lacustrine sandstones, clays, and schists, inter- 
stratified with volcanic rocks, and containing coal-seams. 
These beds have yielded Anthracotherium, plant remains, 
and Corbicula semistriata at the coal-horizon, which is near 
the middle of the series. They are widely spread in southern 
Thrace, and are cut off to the eastward by the falling-in of 
the Marmora sea-bed. ‘The author has traced them along 
the Gallipoli Peninsula to Imbros Island; Lemnos and 
Samothrake are partly composed of similar beds, and he 
considers that all these deposits represent the uppermost 
Eocene and the Oligocene, and that the coal-seams belong 
to the latter. The paper is cou ees by three appen- 
dices, one on the rock-specimens, by J. S. Flett; one 
on the collection of Tertiary and post- ee fossils, by 
Mr. R. Bullen Newton; and a third, by Mr. R. Holland, 
on species of Nummulites.—The Derby earthquakes of 
March 24 and May 3, 1903: Dr. Charles Davison. The 
undoubted earthquakes of this series were four in number. 
The first and strongest occurred on March 24, 1903, at 
1.30 p.m., and was felt over an area of about 12,000 square 
miles, its centre coinciding with the village of Kniveton, 
near Ashbourne. The shock consisted of two distinct parts, 
separated by an interval of about three seconds, which 
coalesced, however, within a narrow rectilinear band 
running centrally across the disturbed area at right angles 
to the longer axes of the isoseismal lines. The isacoustic 
lines (or lines of equal sound-audibility) are very elongated 
curves, distorted along the rectilinear band. The earth- 
quake, it is concluded, was caused by simultaneous slips 
within two detached foci situated along a fault-surface 
running from north 33° east to south 33° west, hading to 
the north-west, and passing close to the village of Hog- 
naston. The strongest after-shock occurred on May 3, its 
focus lying along the same fault, for the most part between 
the two foci of ‘the principal earthquake, but much nearer 
the surface. The principal earthquake was registered by 
an Omori horizontal pendulum at Birmingham, ‘by a Milne 
-, president, in the 
seismograph at Bidston (near Birkenhead), and by a 
Wiechert pendulum at Gé6ttingen (502 miles from the 
epicentre). The larger waves travelled with a velocity of 
29 kilometres per second. 
Chemical Society, March 3.—Dr. W. A. Tilden, F.R.S., 
president, in the chair.—The following papers were read :— 
Chemical dynamics of the alkyl iodides : Miss K. A. Burke 
and F. G. Donnan. The authors have determined the 
velocity of the reaction between silver nitrate and various 
alkyl iodides in alcoholic solution, and have compared the 
results so obtained with those observed by previous workers 
using other reactions of the 
B-crotonic acid from a-crotonic acid : R. S. Morrell! and 
A. E. Bellars. This separation was effected by recrystal- 
lisation of the quinine salts of the mixed acids.—Contribu- 
NO. 1794, VOL. 69] 
alkyl haloids.—Separation of 
tion to the knowledge of the B-diketones: S. Ruhemannm 
and E. R. Watson.—Purification of water by continuous 
fractional distillation: W. R. Bousfield. The apparatus 
consists of a copper boiler provided with a series of ** baffle 
plates’’ to prevent ‘‘ spraying,’’ leading to a condenser 
consisting of a series of test-tubes cooled by adjustable 
streams of water at different temperatures. ‘The distilled 
water which drips from the coldest portions of the con- 
denser is sufficiently pure to be used in electrical conductivity 
experiments.—Freezing point curves of dynamic isomerides. 
Ammonium thiocyanate and thiocarbamide: A. Findlay. 
The freezing point curve consists of two branches meeting” 
at the eutectic point 104-3.—Constitution of phenolphthalein : 
A. G. Green and A. G. Perkin.—é-Ketohexahydrobenzoic 
acid: W. H. Perkin, jun.—Photochemically active 
chlorine: C. H. Burgess and D. L. Chapman.—The 
union of hydrogen and chlorine, part viii., the action of 
temperature on the period of induction: J. W. Mellor. It 
is shown that the period of induction shortens with increase 
of temperature up to 38°; above this point the temperature 
effect is obscured, probably by the influence of the water 
vapour present.—The union of hydrogen and chlorine, part 
ix., further experiments on the action of light on chlorine : 
J. W. Metior. It is shown that the greater chemical 
activity of ‘‘insolated ’’ chlorine is closely related with 
the presence of water vapour.—Additive compounds. 
of unsaturated cyclic ketones with hydrogen cyanide: 
A. C. O. Hann and <A. Lapworth. A _ descrip- 
tion of the additive compounds obtained from  carvone 
and pulegone.—Formation of periodides in organic solvents : 
H. M. Dawson. A study of the potassium periodides. 
formed by the solution of potassium iodide and iodine in 
organic aromatic and aliphatic solvents.—The action of 
sodium hypochlorite on the aromatic sulphonamides: H. S-. 
Raper, J. 1. Thompson and J. B. Cohen. A description 
of the compounds obtained. 
Linnean Society, March 3.—Pro1. S. H. Vines, F.R.S., 
president, in the chair.—Mr. L. A. Boodle exhibited photo- 
graphic lantern-slides demonstrating the formation of 
secondary wood in certain regions of the stem of Psilotune 
triquetrum.—List of the Carices of Malaya: C. B. Clarke, 
F.R.S. After defining his meaning of the term Malaya, 
the author explained that he had been obliged to confine 
his remarks to the material existing at Kew, with certain 
additional specimens lent by Dr. Zahlbruckner, of Vienna, 
who had sent over some of the types of Zollinger’s collec- 
tions. The British Museum herbarium could not be 
utilised, owing to the impracticability of comparing the 
specimens belonging to the two institutions. In all, fifty- 
four species are here enumerated, of which thirty-six, in- 
cluding the eleven here characterised as new, belong to the 
subgenus Caricandra, a natural group essentially tropical 
and difficult to diagnose as to species, all possessing a trifid 
style, with a terminal spike male in the upper portion and 
female at the base.—On some species of the genus Palzemon, 
Fabr., from Tahiti, Shanghai, New Guinea, and West 
Africa: Dr. J. G. de Man.—The species discussed are dis- 
tributed by the author over three subgenera. Relative 
measurements and minute details of various specimens are 
explained and illustrated by drawings, to show the amount of 
variation possible among examples undoubtedly belonging to 
a single species, and on the other hand to offer materials 
for deciding whether forms from two or more widely separ- 
ated localities should be accepted as specifically identical. 
Mathematical Society, March 10.—Dr. E. W. Hobson, 
vice-president, and temporarily Prof. Elliott, vice-president, 
in the chair.—The following papers were communicated :— 
On innex limiting sets of points in a linear interval: Dr. 
E. W. Hobson. Every point of an inner limiting set may 
be enclosed in a sequence of intervals of breadths tending 
to zero in such a way that those limiting points of the set 
which do not belong to the set are not, in the limit, interior 
points of any of the intervals. The cardinal number of the 
points of an inner limiting set is known to be either that 
of the natural numbers or that of the continuum. It is 
shown in the paper that the necessary and sufficient con- 
dition that an enumerable set may be an inner limiting set 
is that it contains no component which is dense in itself. 
The most general character of an inner limiting set which 
is unenumerable is also determined. The importance of the 
