Fill a kettle with water, and set it on the fire; fix a long metal tube
to the spout, and as soon as the water boils, the steam will pass into
the tube, and being condensed into water, will drip at the other end
of the tube, which corresponds with the worm in the still; it soon,
however, becomes as hot as the water, and then the condensation will
cease: but, were the tube passed through cold water, as is the worm of
the still in a tub, the whole water in the kettle might be boiled away,
but reproduced in the tube, and collected from it without the loss of
a drop. This simple process resembles distillation, and the kettle and
tube the still.