APRIL QI, 1912 | 
NATURE 
157 
correlation was found between the pressures and the 
rainfall or sunshine. Specimens of Hedera from a 
north and south aspect were examined, and the former 
were found to have a slightly lower pressure than the 
latter.—Miss Genevieve V. Morrow : The ultimate lines 
of the vacuum tube spectra of manganese, lead, 
copper, and lithium. The author described the 
methods adopted for obtaining the quantitative spectra 
of metals by means of the vacuum tube, and pointed 
out the importance of obtaining such data in order to 
make spectrographic analysis complete. It was 
proved that the presence of an extremely minute trace 
of a substance could be detected by means of these 
tubes; one-tenth of a milligram of a metal gave 
almost a complete spectrum in some cases, and a 
much smaller quantity gave the ultimate lines. 
March 26.—Mr. R. LI. Praeger in the chair.— 
Dr. Jean Timmermans: Experimental researches 
on the density of liquids below o° C. The 
author has devised a method by which the density of 
a liquid below o° can be accurately determined, and 
has established a series of fixed points between 0° and 
—160°. He has determined the boiling points and the 
densities from o° to the freezing points of twenty-five 
carefully purified organic liquids. The law of Cailletet 
and Mathias is not found to hold absolutely even in 
the case of normal pentane. None of the liquids 
examined show a point of maximum density. The 
law of corresponding states, as modified by Mme. K. 
Meyer, is found to hold even at the lowest tempera- 
tures. The ratio of the maximum density (calculated 
at —273°) to the critical density is found to be approxi- 
mately equal to the ratio of the actual to the theoretical 
density in the cases examined.—Dr. A. F. G. Kerr: 
Notes on Dischidia rafflesiana and D. nummularia. 
This is an account of the external morphology of the 
vegetative organs, and of the structure of the flowers 
of these two plants, worked out on fresh material 
gathered in the neighbourhood of Chiengmai, Siam. 
There are also observations on the relationship of the 
plants to the ants which they harbour, and to the 
part played by the latter in the dispersal of the seeds. 
The disposition and the contents of a large series of 
pitchers of D. rafflesiana were examined in situ, and 
it was found that out of 227 pitchers 88 were so 
situated that the retention of water in the pitcher was 
a possibility, while of these only fourteen actually 
contained water. In a discussion of the theories as to 
the functions of the pitchers, the author concludes 
that they are organs for economising water. The 
water vapour given off by the stomata on_the inside 
of the pitchers is absorbed by the nest material of 
the ants, which is plastered over the contained roots 
and is transmitted through them into the plant. 
Paris. 
Academy of Sciences, \pril 1.—M. H. Poincaré in the 
chair —G, Bigourdan: Some observations of position 
which may be made during the solar eclipse of April 
17, 1912. An outline of observations requiring special 
attention during the coming eclipse.—M. Bertin: The 
relation between the increase of displacement of a 
vessel and increase of load.—W. Kilian and Ch. 
Jacob: The non-parallelism of the isopic zones and 
tectonic folds in the Franco-Italian Alps and in the 
Valais.—E. Waelsch: Bipedal functions, triple ortho- 
gonal systems, and isostatic efforts—Arnaud Denjoy : 
An extension of the integral of Lebesgue.—L. E. J. 
Brouwer: The invariance of the closed curve.—A. 
Friedmann: [sodynamic surfaces.—]. Pionchon: The 
solution of copper in water. An element formed of 
two plates of copper with water as liquid shows a 
momentary current when one of the plates is tapped. 
NO. 2215, VOL. 89] 
If the water has been in contact with metallic copper 
for some time, this effect is not observed, and this is 
supposed by the author to be due to the solution of 
minute traces of copper by the water. The amount 
dissolved is too small to be detected by chemical 
means.—P. Vaillant : The influence of temperature and 
of light on the conductivity of a phosphorescent body 
(calcium sulphide). The electrical conductivity of a 
film of calcium sulphide increases under the action of 
light to a maximum and then diminishes. For a 
given apparatus, the relative variations of conductivity 
are independent of the initial conductivity.—R. Fort- 
rat: The telluric bands due to oxygen. It is shown 
that each band may be regarded as being composed 
| of two equal series obeying very nearly the law of 
Deslandres.—G: A. Hemsalech: The relative velocities 
of the luminous vapours of various elements in the 
electric spark. Applying the experimental method 
developed in previous papers, it is shown that the 
elements studied can be divided into groups, in each 
of which there is a relation between the velocities of 
the vapours in the spark and the atomic weights.—A. 
Aubertin : The appearances of the discharge of a con- 
denser.—Louis Hackspill: The vapour pressure of the 
alkaline metals between 250° C. and 400° C. The 
metal was sealed in a U tube, one limb of which was 
maintained just above the melting point of the metal 
and the other at the temperature at which the vapour 
pressure was required. The vapour pressures 
were determined from the observed change of 
level in the two arms of the tube. The results 
obtained are shown graphically for caesium, rubidium, 
potassium, and sodium.—Alfred Henry: The deter- 
‘ mination in absolute value of the mass of the mole- 
| tion points at 125° and 716°. 
| discharge. 
| these a cure was effected 
cules of liquids, and more especially that of the 
mercury molecule.—Marcel Boll and Paul Job: The 
photochemical kinetics of the chloroplatinic acids in 
verv dilute solutions. The decomposition of the chloro- 
platinic acids, H.PtCl,, H.Pt(OH)C1,, H.Pt(OH).Cl,, 
and H.Pt(OH),ClL, by the light from a mercury arc 
was studied in tenth-millinormal solutions; in each 
case the reaction was found to be bimolecular.—P. 
Pascal: Thermal analysis of hexachloroethane and its 
binary mixtures. The cooling curve of solid hexa- 
chloréethane showed that three forms exist with transi- 
The melting points of 
mixtures of hexachloroethane with naphthalene and 
with phenanthrene were also studied, and the results 
shown graphically.—M. Lespieau : The dimethyl ether 
of 1: 5 pentinediol and its hydrogenation.—A. Guillier- 
mond: The mitochondria of the sexual organs of 
plants.—Raoul Combes: A method for the culture of 
the higher plants in sterile media. An apparatus 1s 
ficured and described in which the roois of a growing 
plant remain in a medium rigorously sterile whilst 
the stem and leaves are in the open air.—F. Jadin 
and A. Astrug : The presence of arsenic in some plants 
used as food. The researches of Gautier and G. 
Bertrand have definitely demonstrated that arsenic 
exists normally in man and animals. The examina- 
tion of a number of edible plants and fruits shows 
that some of this arsenic may be taken as vegetables. 
Arsenic was found in all the thirty-nine substances 
examined in quantities between o'03 part per million 
in the leek and o'25 part per million in almonds 
and beans.—H. Arsandaux: The presence of rocks 
belonging to the charnoclkite series at, Gabon.—R. 
Tronquoy: Modification of the tin-bearing lodes of 
Villeder (Morbihan).—M. Laquerriére : First results of 
the application to gynecology of the electrolysis of 
radium salts (Haret’s method)._—E. Doumer: The 
treatment of tubercular osteitis by the high-frequency 
Eleven cases were treated, and in all 
, the time taken varying from 
