Action of Platinum on Combustible Gases. 18} 
in the ease observed in the Isle of Wight it was above it.— 
The reflected light would then come to the eye in the same 
manner as the direct light of the sun, in passing through the 
fissures of clonds covering the sun; and the same effect of 
perspective would follow. 
In the second instance, the effect might have been produced 
as explained by the writer in the Journal of the Royal Insti- 
tution; since there were clouds intervening between the sun 
and the place of radiation, alihough there were none between 
the sun and the spectator ; still the explanation I bave given 
of the first case, would be equally applicable here.—Indeed, 
I think the appearance in the Isle of Wight might be explain- 
ed in the same way; since the writer acknowledges there was 
quite a dense haze in the eastern horizon ;—and it does vot 
appear to me necessary that vapour shofild assume the defi- 
nite form of cloud, to produce such effects of reflection and 
perspective. J. G, PERCIVAL.. 
Il. FOREIGN. 
Action of Platinum on combustible Gases mixed with Ozx- 
izen—Dr. Wa. HENRY, to whom chemistry is indebted for a 
was consumed. The wire, repeatedly taken out of the mis- 
ture, and suffered to cool below the points of redness, instant- 
ly recovered its temperature on being again plunged into the 
mixed gases, The same phenomena were produced in mix- 
very fine, and the gases had been mixed in explosive propor-_ 
tions, the heat of the wires became sufliciently intense te 
