e fresh
material, cannot of course be so closed, but whether he lives or dies,
if the above be observed, he will leave no infection behind him.[22]

[Footnote 21: The oven on that account need not lose character with
bread-eaters, for according to the old adage, Omne vitium per ignem
excoquitur.]

[Footnote 22: Light too, more especially when assisted by a current
of atmospheric air, is a true and sure disinfectant, but it is not so
applicable as heat in the common contagions, from requiring an exposure
of the infected substances for days together, or even a longer period,
before it can be made effective.]

It is now time to bring this tedious letter to a close; I shall be
happy, through the same channel, to give any information, or answer any
inquiries that may be authenticated by the signature of the writer; but
anonymous writing of any kind, I shall not consider myself bound to
notice. Should the dreaded disease spread its ravages throughout our
population, I may then, at some future early opportunity, trusting to
your indulgence, trespass again upon your columns with further
communications on this most interesting subject.

WILLIAM FERGUSSON,
Inspector-General of Hospitals.

P.S.--Throughout the foregoing letter, I have used the words contagion
and infection as precisely synonymous terms, meaning communicability
of disease from one person to another.

_November 9, 1831._

LETTER II.

TO THE EDITOR OF THE WINDSOR EXPRESS.

Sir,--In my last letter, I treated of the practicability of guarding
our country against the now European and Continental disease, malignant
Cholera Morbus, by quarantine regulations. In the present one, it is
my intention still in a popular manner to scrutinise more deeply,
the doctrine of imported contagions; to point out, if I can, those
true contagions which can be warded off by our own exertions, in
contradistinction to others which are altogether beyond our controul;
and here it may be as well to premise, that when I use the term
epidemic, I mean atmospheric influence, endemic-terrestrial influence,
or emanation from the soil; and by pestilential, I mean the spread of
malignant disease without any reference to its source. The terms
contagion and infection have already been explained.

It must be evident, that legislative precaution can only be made
applicable to the first of these. The last being unchangeable by human
authority, are not to be assailed by any decrees we c