that subject was so plausible, and well
adapted to the understanding of his hearers, that any person who had not
actually studied the medical art would have believed he was inspired by
the spirit of Aesculapius. What contributed to the aggrandisement of his
character in this branch of knowledge, was a victory he obtained over an
old physician, who plied at the well, and had one day unfortunately begun
to harangue in the pump-room upon the nature of the Bristol water. In
the course of this lecture he undertook to account for the warmth of the
fluid; and his ideas being perplexed with a great deal of reading, which
he had not been able to digest, his disquisition was so indistinct, and
his expression so obscure and unentertaining, that our hero seized the
opportunity of displaying his own erudition, by venturing to contradict
some circumstances of the doctor's hypothesis, and substituting a theory
of his own, which, as he had invented it for the purpose, was equally
amusing and chimerical.

He alleged, that fire was the sole vivifying principle that pervaded all
nature; that, as the heat of the sun concocted the juice of vegetables,
and ripened those fruits that grow upon the surface of this globe, there
was likewise an immense store of central fire reserved within the bowels
of the earth, not only for the generation of gems, fossils, and all the
purposes of the mineral world, but likewise for cherishing and keeping
alive those plants which would otherwise perish by the winter's cold.
The existence of such a fire he proved from the nature of all those
volcanoes, which in almost every corner of the earth are continually
vomiting up either flames or smoke. "These," said he, "are the great
vents appointed by nature for the discharge of that rarefied air and
combustible matter, which, if confined, would burst the globe asunder;
but, besides the larger outlets, there are some small chimneys through
which part of the heat transpires; a vapour of that sort, I conceive,
must pass through the bed or channel of this spring, the waters of which,
accordingly retain a moderate warmth."

This account, which totally overthrew the other's doctrine, was so
extremely agreeable to the audience, that the testy doctor lost his
temper, and gave them to understand, without preamble, that he must be a
person wholly ignorant of natural philosophy, who could invent such a
ridiculous system, and they involved in worse than an Egyptian fog, that