induced to deliver this lecture. It
has been honoured with the attention of numerous audiences, in some
of the most populous towns in England, where it has generally been
read for the benefit of charitable institutions._

_The author flatters himself, that besides the benefit produced by
his humble endeavours to serve these institutions, those endeavours
have not totally failed in the grand object of preserving health;
and with the hope that the influence of the precepts here given, may
be farther extended, he has concurred in the ideas of those who have
advised the publication of this lecture._

_It is to be feared, that notwithstanding all which can be done,
disease will continue to be a heavy tax, which civilized society
must pay for its comforts; and the valetudinarian will often be
tempted to envy the savage the strength and soundness of his
constitution. Much however may be done towards the prevention of a
number of diseases. If this lecture should contribute to the
attainment of so desirable an end, it will afford the highest
gratification to the author._

_The first part of the lecture is the substance of an essay which was
read by the author before the Royal Medical Society of Edinburgh,
intended as a defence of the general principles of the system of Dr.
Brown, whose pupil he then was. It was, according to custom,
transcribed into the books of the society, and the public have now
an opportunity of judging how far Dr. Girtanner, in his first
essay published in the Journal de Physique, about two years after,
in which he gives the theory as his own, without the least
acknowledgment to the much injured and unfortunate author of the_
Elementa Medicinae, _has borrowed from this essay._

_In public lectures, novelty is not to be expected, the principal
object of the lecturer being to place in a proper point of view,
what has been before discovered. The author has therefore freely
availed himself of the labours of others, particularly of the
popular publications of Dr. Beddoes, which he takes this opportunity
of acknowledging._

_This lecture is published almost_ verbatim _as it was delivered. On
this account the experiments mentioned are not minutely described,
the reader being supposed to see them performed._

* * * * *

A LECTURE,
&c.

THE greatest blessing we enjoy is health, without it, wealth,
honors, and every other consideration, would be insipid, and even
irksome; the preservation of this state