May 29, 1902] 
NATURE 
119 
F. G. Donnan. The measurements were made by a modifica- 
tion of Ramsay and Shield’s method between 70° and 9go° 
absolute, and the results were found to be in accordance with 
the view that these liquids consist of non-associated molecules. 
The critical temperatures deduced from these observations are 
in agreement with those directly determined for oxygen and 
nitrogen, but not with the values assigned to argon and carbon 
monoxide for this constant.—Comparison of bromonitrocam- 
phane with bromonitrocamphor, by Dr. M. O. Forster. The 
action of various reagents on bromonitrocamphor has been ex- 
amined in the hope of isolating derivatives of the latter substance 
analogous to those obtained from bromonitrocamphane, but in 
most cases the reactions proceed either further or in a different 
sense.—aa-Benzoylnitrocamphor and aa-benzoyliodocamphor, 
by Dr. M. O. Forster and Mr. E. A. Jenkinson. A descrip- 
“tion of these substances and several of their derivatives is given 
illustrating the peculiar aa’-isomerism of substituted camphors. 
—2:4-Dibromo-s-nitro- and 2: 4-dibromo-3 : 5-dinitrotoluenes 
and their behaviour on reduction, by Mr. W. A. Davis. These 
substances are produced by the direct nitration of 2: 4-dibromo- 
toluene, and on reduction furnish respectively 4 : 6-dibromomefa- 
toluidine and syz.tolylene diamine.—The purification of hydro- 
chloric acid from arsenic, by Dr. Thorne and Mr. E. H. Jeffers. 
The purification of hydrochloric acid to be used in testing for 
arsenic may be accomplished by digesting in it pieces of bright | 
copper gauze, so long as these become stained by the deposition 
of arsenic on their surface.—The radioactivity of thorium com- | 
pounds, and the cause and nature of radioactivity, by Prof. 
Rutherford and Mr. Soddy. Thorium, from which the radio- 
active substance Th.X has been separated, regains its activity 
after a time, while that of Th.X. slowly disappears. 
This | 
production and disappearance of activity is not affected by any | 
known agents, and proceeds independently of the physical and | 
chemical conditions of the molecule ; the authors believe that 
the source of this energy is to be found ina chemical change 
producing new types of matter.—The radioactivity of uranium, 
by Mr. F. Soddy. Prof. Rutherford has already shown that 
uranium exhibits a dual radiation, one, a, having little action on a 
photographic plate and a second, 8, almost inactive to the 
electrometer under ordinary conditions. The author now finds 
that the substance Ur.X isolated from uranium possesses only the 
f-radiation, the a-effect being retained by the parent substance. 
Royal Meteorological Society, May 21.—Mr. W. H. 
Dines, president, in the chair.—Captain D. Wilson-Barker read 
a report prepared by Mr. Dines and himself on the wind force 
experiments which had been made on H.M.S. /Vorcester off 
Greenhithe and at Stoneness Lighthouse, 817 yards from the 
ship on the north bank of the river. These experiments were 
in continuation of those on the exposure of anemometers at 
different elevations which were carried out on the Worcester a 
few years ago. All the observations were made with the 
pressure-tube anemometer. The broad general result is that 
the lighthouse experiences steadier and stronger winds than the 
Worcester, the velocity being about 6 per cent. greater, not- 
withstanding the fact that the elevation is less than half, but 
that in both positions the extreme velocities reached in the 
gusts are about equal.—Dr. H. R. Mill read a paper on the 
Cornish dust fall of January, 1902. When the west of England 
newspapers of January 24 announced falls of ‘‘ pink snow” and 
** muddy rain” in several parts of Cornwall and South Wales, | 
it seemed to the author possible that fresh light might be thrown 
on what is at present the chief object of progressive meteorology, 
viz. the movements of the upper air. He therefore took steps 
to collect as much information as possible from the whole of 
the district, and found that the phenomenon was reported from | 
seventy-five different places in the south-west of England and 
Wales. These were all south of a line joining Milford Haven 
and Chepstow, and west of the meridian of Bath. By means of 
a map, Dr. Mill showed that four separate areas were visited by 
the dust between January 21 and 23, viz. (1) Cornwall, 1400 
square miles ; (2) North Devon, 150 square miles ; (3) Milford | 
Haven, 50 square miles; and (4) Bristol Channel, 600 square 
miles. The dust appears to have been confined mostly to low 
rather than high ground, for none was reported to have fallen 
on the Mendip Hills, Dartmoor, Exmoor and the Welsh 
mountains. The observations show that January 22 was un- 
doubtedly the day when most falls occurred and that the colour 
of the dust was yellowish or brownish. From a consideration 
of the meteorological conditions at the time and for several 
NO. 1700, VOL. 66] 
| whose papers the manuscript had been found. 
| in the chair.—On the optical arrangements 
days before, the author is inclined to believe that the evidence 
points to the dust having been transported in the upper air 
from the African deserts. 
EDINBURGH. 
Royal Society, May 5.—Prof. Geikie in the chair,—A 
paper was communicated by Prof. Beattie on the leakage of 
electricity from charged bodies at moderate temperatures (part 
ili.). The paper described a great variety of experiments in 
which such substances as common salt, lithium chloride and 
potassium bichromate, when laid on zinc and sprinkled with 
iodine or bromine, and then raised to a temperature between 
300° and 350° C., caused electrification of the surrounding 
atmosphere of air, coal gas, oxygen or carbonic acid gas, 
Hydrogen was not electrified under similar conditions. The 
effects differed from those produced in other ways. Thus, in 
addition to the well-known electrifying properties of flames 
and their fumes, there seem to be three distinct methods of 
obtaining an electrified gas by heating: (1) by oxidation or 
deoxidation as in the atmosphere drawn from the neighbour- 
| hood of oxidising or deoxidising metals (Schuster), (2) by 
driving off a gas which carries a charge with it as in the case 
of the gas obtained by heating potassium permanganate (Town- 
send), (3) by the methods described in the present paper.— 
Prof. MacGregor communicated a paper by the late Prof. C. 
Piazzi Smyth, Does the spectrum place of the sodium lines vary 
in different azimuths ? The paper bore the date May 25, 1882, 
and the investigation had been suggested by Prof. Tait, among 
The apparatus 
used consisted of a Rutherford grating with 17,296 lines to the 
inch, the necessary collimator and telescope, and an end-on 
vacuum tube containing sodium vapour. The whole was set up 
ona rotating table, and measurements of the positions of the 
D lines were made in various azimuths. The results were 
negative. An idea of the sensitiveness attained may be gained 
from the statements that the two principal D lines were 
separated by 266 micrometer divisions, and that the probable 
error of observation was two of these divisions. 
PARIS. 
Academy of Sciences, May 20.—M. Bouquet de la Grye 
necessary for 
remedying the visual troubles in cases of keratoconia, by M. J. 
Janssen. A description of a lens system by means of which 
the effect of this disease can be almost entirely compensated. — 
On the composition of the ashes projected from Mont Pelée on 
May 3, 1902, by M. Michel Levy. Andesine and hypersthene 
were recognised as the chief constituents of the volcanic ash. — 
On the spermatogenesis of the diptera of the genus Sciara, by 
M. Alfred Giard. The emission of the spermatic elements in 
Sciara is accompanied by phenomena nearly as complicated as 
in the Cephalopods. There is no production of a capsule form- 
ing a true spermatophore.—The addition of hydrogen to ethyl- 
enic hydrocarbons by the method of contact, by MM. Paul 
Sabatier and J. B. Senderens. The catalytic action of reduced 
nickel and copper in causing the addition of hydrogen to un- 
saturated hydrocarbons has been extended to propylene, tri- 
methylethylene, hexene and octene. Propylene mixed with 
hydrogen in excess is readily transformed by reduced nickel at 
160° C. into propane; copper behaves similarly, but the re- 
action is slower. Trimethylethylene is similarly converted into 
pure methylbutane in the presence of nickel, but copper is 
without action in this case. It has been found that copper and 
nickel are equally capable of effecting the addition of hydrogen 
in the case of ethylene derivatives containing the grouping 
=CH,, but that compounds of the type R.C=CR’ do not 
add on hydrogen under the action of copper. Application is 
made of this to the case of limonene, with the result that the 
formula ordinarily attributed to it, representing it as containing 
a =CH, group, is confirmed.—On the arithmetical properties 
of entire and quasi-entire functions, by M. Edmond Maillet.— 
On the repulsive force and electrical actions emanating from the 
sun, by M. H. Deslandres. A criticism of the views of S. 
Arrhenius, with some remarks on the nature of nebulz.—On the 
constitution of matter and spectroscopy, by M. B. Eginitis. 
The author regards the elimination of air lines in Schuster and 
Hemsalech’s work on spark spectra as being chiefly due to the 
metallic vapours produced. —The action of light on precious stones, 
by M. Chaumet. A connection is shown to exist between the 
