rn we saw some tall and beautiful stalactite pillars.

The water drips from the roof charged with bicarbonate of lime.
Exposed to the air, the carbonic acid partially escapes, and the
simple carbonate of lime, which is hardly at all soluble in water,
deposits itself as a solid, forming stalactites and stalagmites. Even
the exposure of chalk or limestone water to the open air partially
softens it. A specimen of the Redbourne water exposed by Professors
Graham, Miller, and Hofmann, in a shallow basin, fell from eighteen
degrees to nine degrees of hardness. The softening process of Clark
is virtually a hastening of the natural process. Here, however,
instead of being permitted to evaporate, half the carbonic acid is
appropriated by lime, the half thus taken up, as well as the remaining
half, being precipitated. The solid precipitate is permitted to sink,
and the clear supernatant liquid is limpid soft water.

We returned to the real mouth of St. Michael's Cave, which is entered
by a wicket. The floor was somewhat muddy, and the roof and walls
were wet. We soon found ourselves in the midst of a natural temple,
where tall columns sprang complete from floor to roof, while incipient
columns were growing to meet each other, upwards and downwards. The
water which trickles from the stalactite, after having in part yielded
up its carbonate of lime, falls upon the floor vertically underneath,
and there builds the stalagmite. Consequently, the pillars grow from
above and below simultaneously, along the same vertical. It is easy
to distinguish the stalagmitic from the stalactitic portion of the
pillars. The former is always divided into short segments by
protuberant rings, as if deposited periodically, while the latter
presents a uniform surface. In some cases the points of inverted
cones of stalactite rested on the centres of pillars of stalagmite.
The process of solidification and the consequent architecture were
alike beautiful.

We followed our guide through various branches and arms of the cave,
climbed and descended steps, halted at the edges of dark shafts and
apertures, and squeezed ourselves through narrow passages. From time
to time we halted, while Mr. Crookes illuminated with ignited
magnesium wire, the roof, columns, dependent spears, and graceful
drapery of the stalactites. Once, coming to a magnificent cluster of
icicle-like spears, we helped ourselves to specimens. There was some
difficulty in detach