DUST-SHOWERS AND RED-RAIN.


Recent scientific investigations in Europe and America have thrown
some interesting light on the nature of these very curious phenomena.
The results arrived at may be brought familiarly before our readers.

Mr Charles Darwin, in the narrative of his voyage in the _Beagle_,
states that while he was at St Jago, one of the Cape de Verd islands,
in January 1832: 'The atmosphere was generally very hazy; this appears
chiefly due to an impalpable dust, which is constantly falling, even
on vessels far out at sea. The dust,' he goes on to say, 'is of a
brown colour, and under the blow-pipe, easily fuses into a black
enamel. It is produced, as I believe, from the wear and tear of
volcanic rocks, and must come from the coast of Africa.' The same
opinion was held by scientific men generally, as well of the dust met
with in the North Atlantic, as of that which sometimes falls on the
islands and shores of the Mediterranean: Africa was supposed to be the
original source of the air-borne particles. Some of the dust, however,
having been sent to Ehrenberg of Berlin, that celebrated _savant_,
after a microscopical examination, laid an account of his inquiry
before the Akademie der Wissenschaften, in May 1844, in which he
shewed that the dust, so far from being inorganic, contained numerous
specimens of a species of flint-shelled animalcules, or infusoria,
known as polygastrica, and minute portions of terrestrial plants. The
investigation led him to certain conclusions: '1. That meteoric
dust-rain is of terrestrial origin. 2. That the same is not a rain of