ish River Caves the fantastic shapes assumed by the limestone
formations are infinite in variety, as well as weird and singular in
their groupings. But perhaps they excel most particularly in their
beautiful coloring, in many instances presenting great brilliancy of
lustre, which causes the individual stalactites to seem like ponderous
opals.

A magnesium wire is introduced by the guide for the pleasure of the
visitor, and when the caves are thus illumined the most fairy-like
effect is produced. It is as if one suddenly stood within the charmed
palace of Aladdin, the gauze-like fountains reflecting the light upon
one another like a series of mirrors, and the whole sparkling like
rubies, emeralds, and diamonds. The effect then becomes fantastic,
unreal, theatrical. From some of the intricate windings the distant
music of waterfalls strikes pleasantly on the ear, and crystal streams
reflect the light in azure hues. When the guide extinguishes for a
moment his powerful light, gloom and darkness surround the visitor,
stimulating the imagination to vivid activity. These might be the caves
of Erebus leading to Hades, and where is Charon to ferry us across the
Styx? May not that distant sound of falling water be the voice of Lethe,
that river of oblivion "whereof whoso drinks straightway his former
sense and being forgets"? Some of these natural temples have domes
rivalling St. Peter's and St. Paul's. How many there are of these caves,
running for miles into the mountains, no one can say, as they have never
been fully explored; but every year some new grotto is discovered and
added to the number already recorded.

Caves of limestone formation are produced in many parts of the world,
and the simplest knowledge of chemistry coupled with a little careful
observation shows us clearly how they have been created. The conditions
must first be those of an underlying bed of limestone nearly horizontal
in its layers, over which a forest or wooded surface has grown. The
falling rain washes the decaying leaves, and in doing so borrows from
them certain chemical properties, charged with which the water sinks
into the limestone beds. The carbon acquired by the water combines with
and dissolves the lime and other components of the rock, which then
escape as gases through the interstices of the earth. Thus openings are
at first formed, which are slowly increased in size by the same process
during the passing ages, until vast and curious cave