was no motion in the mass which might have caused the
infinitesimal droplets to collide and to coalesce into
something perceivable to my senses.

Once, of a full-moon night, I spent an hour getting into
a pool like that, and when I looked down at my feet, I
could not see them. But after I had been standing in it
for a while, ten minutes maybe, a clear space had formed
around my body, and I could see the ground. The heat of
my body helped the air to redissolve the mist into steam.
And as I watched, I noticed that a current was set up.
The mist was continually flowing in towards my feet and
legs where the body-heat was least. And where evaporation
proceeded fastest, that is at the height of my waist,
little wisps of mist would detach themselves from the
side of the funnel of clear air in which I stood, and
they would, in a slow, graceful motion, accelerated
somewhat towards the last, describe a downward and inward
curve towards the lower part of my body before they
dissolved. I thought of that elusive and yet clearly
defined layer of mist that forms in the plane of contact
between the cold air flowing from Mammoth Cave in Kentucky
and the ambient air of a sultry summer day. [Footnote:
See Burroughs' wonderful description of this phenomenon
in "Riverby."]

On another of the rare occasions when the mists had formed
in the necessary density I went out again, put a stone
in my pocket and took a dog along. I approached a shallow
mist pool with the greatest caution. The dog crouched