THE NATURALIST.

[Illustration: FLAKES OF SNOW MAGNIFIED.]



Snow is one of the treasures of the atmosphere. Its wonderful
construction, and the beautiful regularity of its figures, have been the
object of a treatise by Erasmus Bartholine, who published in 1661, "_De
Figurâ Nivis Dissertatio_," with observations of his brother Thomas on
the use of snow in medicine. On examining the flakes of snow with a
magnifying glass before they melt, (which may easily be done by making
the experiment in the open air,) they will appear composed of fine
shining spicula or points, diverging like rays from a centre. As the
flakes fall down through the atmosphere, they are joined by more of these
radiated spicula, and thus increase in bulk like the drops of rain or
hail-stones. Dr. Green says, "that many parts of snow are of a regular
figure, for the most part so many little rowels or stars of six points,
and are as perfect and transparent ice as any seen on a pond. Upon each
of these points are other collateral points set at the same angles as the
main points themselves; among these there are divers others, irregular,
which are chiefly broken points and fragments of the regular ones. Others
also, by various winds, seem to have been thawed and frozen again into
irregular clusters; so that it seems as if the whole body of snow was an
infinite mass of icicles irregularly figured. That is, a cloud of vapours
being gathered into drops, those drops forthwith descend, and in their
descent, meeting with a freezing air as they pass through a colder
region, each drop is immediately frozen into an icicle, shooting itself