TRANSACTIONS OF THE SECTIONS. 27 
(for part of the time) rain-gauge. The wind is recorded in direction and estimated 
in force; and the state of the sky and character of weather are noticed several times 
daily. 
‘The hours for registration of instruments are sunrise, 9 a.m., 2 P.M., sunset, 9 P.M. 
The max. min. and range of the daily observations are entered, with the several ob- 
servations in tables. [After the 7th of October the observations were taken at Calabar 
Barracks.] We extract the following general results :— 
; i Extreme 
Extreme | Extreme Mean diff. 
Mean Mean diff. of Dry 
Mean Temp. s A of Dry and 
P-| Max. Temp.|Min. Temp-|Max. Temp.|/Min. Temp. Wet Bulb. ae 4 
— | ——— | | SS | Le, | 
August .....} 81:3 83°8 78°8 86°5 77:0 4°1 75 
September..| 81-7 84:7 78°8 89:0 76°8 5:0 9-0 
October.....| 85°0 89°9 80°1 97-2 74:0 79 10°6 
New Experiments on Electro-Magnetism. By Prof. WARTMANN. 
Since the discovery made last year, by Dr. Faraday, of the action of magnets upon 
polarized light passing through different media, it became interesting to ascertain 
whether this influence is limited to the rotation of the plane of polarization of the ray. 
Numerous experiments have shown that no change whatever is undergone by the 
fixed lines of the spectrum, either in position, or in quantity or visibility, when they 
are produced by rays of natural or artificial light, common or polarized, which have 
_ been made to go through different substances, such as air, nitrous acid gas, water, 
_ alcohol, oil of turpentine, syrup of sugar, a solution of ferruginous alum, or a long 
prism of flint glass, put in the sphere of action of powerful electro-magnets. As 
far as those researches have been brought, they lead to the conclusion, that neither 
light nor the medium suffers any constitutional derangement which could alter the 
_ property of the ray to be partially absorbed when it is refracted through a prism. 
The view generally entertained by foreign philosophers as to the real action of the 
magnet being one upon the material substance which gives way to the luminous ray, 
_ it became necessary to test whether the new magnetical state of molecular equilibrium 
_ would not be concordant with some new properties of chemical affinity. Indeed, it 
has long ago been asserted by Ritter, Fresnel, Hansteen, Murchmann, Lodeck, Mur- 
ray and others, and more recently by Mr. Hunt, that the magnets have a decided in- 
fluence upon chemical phenomena. I have taken advantage of powerful electro- 
_ magnets, which are put in action by sixty pairs of Bunsen’s battery, to make some 
_ fresh trials upon the subject, convinced that such means would afford me an oppor- 
tunity of witnessing, if any, far more decisive actions than those which have been 
described. But all my attempts have proved unsuccessful to produce any difference 
in the electrolysis of acidulated water of ferruginous dissolutions, or in the electro- 
chemical decomposition of sulphate of copper, or of acetate of lead by soft iron. All 
the results have been carefully and repeatedly tested by accurate weighings; and in 
the case of the electrolysis of water, 1 employed electrodes of soft iron gilt by elec- 
trical process, and supported by the very poles of the magnets, with the interposition 
of a film of mica as thin as possible. The apparatus have been placed in all direc- 
tions relative to terrestrial magnetism, and the poles of artificial magnets have been 
made to act both separately or together, without any different result whatever. But 
_ in expressing this my opinion, I must add that I mean not to say that magnetism is 
not able to interfere with molecular disposition, which is quite a different view of the 
_ subject, though it has not perhaps been sufficiently distinguished from the former one. 
Indeed we have ample evidence that this is the case under favourable circumstances, 
‘These experimental inquiries have led me to ascertain two facts which it may perhaps 
not be improper to state here. Ifa chemical action is produced by the immersion of 
two pieces of soft iron into a liquid which is able to corrode them, or to be decom- 
posed by the metal, and if the poles of a magnet be applied upon these cores, an elec- 
u 
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