had done it, he judged it
expedient to publish that opinion; to which I gave my consent. It was
published in the _Journal of Humanity_; and for substance it was made up
of an abridgement of Dr. McAllister's views, and some strictures on his
style and method of treating the subject. In particular, a desire was
expressed that Dr. McA. would discuss more fully some of the arguments
employed in defence of using tobacco. This critique was sent to the
author of the Essay; who in consequence of it expressed a willingness to
revise his work, and make such additions as had been suggested. Some
weeks since he transmitted to me a copy of the original edition, with a
manuscript containing the Appendix to the present edition. At the same
time he requested me to make any alterations in either part, which I
might deem expedient. I have used this liberty so far as to change a few
_technical_ words for popular and intelligible ones. In some of these
cases, I have detracted from the _specific_ accuracy of the writer, as a
medical man, for the sake of making his expressions more intelligible to
the mass of readers. What he will thus lose, in his reputation for
scientifical accuracy, he will gain by becoming more useful. A few other
slight alterations and modifications have been made; but only such as I
judged the worthy author would at once cheerfully admit. I have kept
within the bounds of the liberty which he gave me; and I trust he will
not be dissatisfied with what I have done.

I command the serious perusal of the following Essay and Appendix to
every man, who wishes to become well informed respecting the properties
of tobacco. Whoever uses this substance as a luxury, is bound by a due
regard to his own physical welfare to make himself acquainted with its
properties and their influence. If any man can soberly peruse the
following pages, without conviction that he is "playing with
edge-tools," while he is indulging in the use of tobacco, I must confess
his mind to be of a composition different from mine.

One word as to _breaking off the habit_. The difficulty, I fully
believe, is not much less than the breaking off from ardent spirits. But
as to any danger to health in breaking off, the fear is idle; excepting
in case of delicate habits, where small changes produce great effects;
or in case of advanced years and inveterate habit, where the course of
those fluids which are so much affected by tobacco, if suddenly and
entirely changed