28 C. Abbe on the transparency of the Atmosphere. 
zone—positive-electrized oxygen—in the atmosphere?” We see 
at once that the former question may be regarded as answered 
when the latter finds a satisfactory reply. Meissner considers 
himself warranted in assuming that what he has shown to be 
true in the combustion of phosphorus and hydrogen is typical 
of all processes of oxydation by atmospheric oxygen, and that, 
accordingly, this element suffers polarization in every instance 
where its affinities are exerted. “A bit of phosphorus with its 
immediate surroundings of air and water, in which it slowly 
Se raaee of the to oes it discusses, and the PeilicoboMG a ae 
everywhere exhibited by the author. e are bound to say that 
the assumption of the formation of nitrite of ammonia from nitro- 
gen and water is refuted by Meissner, and the true origin of the 
oxyds of nitrogen that occur in nature is satisfactorily explained. 
The ozone question by these researches acquires a broader basis 
and more consistent aspeet than it has hitherto possessed, and 
the new fields of investigation that are displayed through thsead 
pages are full of invitation and of promise, 
Arr. IIL—On the Transparency of the Earth’s Atmosphere; by 
CLEVELAND ABBE. 
Bovucuer in his Traité d’ Optique and Laplace in his Mécanique 
Céleste have investigated the effect of the earth’s atmosphere in 
absorbing the light of celestial luminaries. The latter has shown 
that, approximately, the logarithm of the intensity of their ns 
varies inversely as the cosine of their zenith distance, and, m 
nearly, as the quotient of the refraction divided by the sine of 
the zenith distance. 
If, then, assuming any unit of comparison, we observe the in- 
tensity iat the zenith distance 4, and the intensity I at the ze- 
nith distance zero, the intensity ol before entrance into the 
ee ephere being put at 2,, we have 
. log — 
—Q.(0).2 E, 
dog Aas es a aa) Bs or log E= —2— eet 7 F (1) 
: % 
EE Bi 6 i is a constant to be determined, (¢) is the density of © 
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