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POPULAR SCIENCE REVIEW. 
matic effect is displayed ; the colours of the spectrum will he seen distributed 
in an elliptical shape. Cylinders of solid glass, submitted to the same expe- 
riment, exhibit somewhat similar phenomena, but less conspicuously than 
fluids. — Comptes rendus, Oct. 25. 
Electric Phenomena of the Solution of Salts in Water. — M. Raoult in a 
paper in the Comptes rendus says that the dissolution of a salt in water is 
a complex phenomenon whereby we distinguish — 1st, the fusion (melting), 
or disintegration of the salt, whereby heat is absorbed ; 2nd, the diffusion of 
saline molecules in water, which also absorbs heat ; 3rd, the combination of 
the salt with water, whereby heat is set free. The author then states that 
the conditions alluded to under Nos. 1 and 2 do not produce any electricity, 
but that, on the other hand, the combination of a salt with water certainly 
does give rise to an electric current, to prove which the author records a 
series of experimental results. — Comptes rendus, Oct. 11, and Chemical Hews. 
The Force of Sea-waves utilised . — At the Societe philomathique of Paris, 
on October 23, a paper was read by M. de Caligny on a new application 
of centrifugal force in one of his machines for effecting drainage by means of 
sea-waves. In this apparatus, already described to the Society, the water 
enters from the marsh to be drained into the apparatus at each oscillation 
occasioned in it by the waves, and cannot return in consequence of the closing 
of a valve. The present paper describes the various arrangements of the 
apparatus to suit different circumstances. Drawings of this apparatus are to 
be seen in the recent numbers of M. de Cuyper’s Revue universelle. 
Peculiar Luminous Effects . — M. E. Becquerel has published a fifth memoir 
of his researches on the luminous effects produced by the action of light 
upon bodies. This memoir treats of the refrangibility of the active rays. 
He has endeavoured to study the action of rays of different refrangibility on 
phosphorescent bodies. He has now established, with different substances 
— alumina, lime-salts, uranium -salts, &c., as he had already done with the 
sulphides of the alkaline earths in which the phosphorescence persists for a 
long time — that each substance behaves in a particular manner, and presents 
one or more active spaces unequally distributed in the luminous spectrum ; 
and, further, that it is the base of the impressionable chemical compound 
which appears to give its specific character not only to the emitted rays, but 
also to their refrangibility, and to the extent of the active space. — Comptes 
rendus , Nov. 15. 
Magnetic Storms and Aurorce. — At a late meeting of the Academy of 
Sciences of St. Petersburg, M. Wild reported upon the aurorae boreales of 
April 15 and 16, and May 13 and 14 last, and on the relations which 
exist between these phenomena and magnetic perturbations. On April 14, 
a very severe magnetic storm was recognised by the people in charge of the 
electric telegraphs, but the cloudy condition of the sky prevented the aurorae 
being seen, and thus the cause recognised. All the directors of the Russian 
observatories reported simultaneous magnetic disturbances of a similar 
order. M. Wild remarked also that similar perturbations were recorded in 
Eiance, England, Italy, and all over Europe. The aurora of May 13 fur- 
nished another example of the same kind. On this occasion M. Rudneff called 
M. Wild to show him the extraordinary oscillations of the magnetic needles. 
In spite of an attentive observation of the northern sky, no trace of aurora 
