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                                A SHORT
                               DISCOURSE
                               CONCERNING
                       _Pestilential Contagion_,
                                AND THE
                                METHODS
                       To be used to Prevent it.


                        By _RICHARD MEAD_, M.D.
                  Fellow of the College of Physicians
                       and of the Royal Society.

[Illustration]

                               _LONDON_:
            Printed for _Sam. Buckley_ in _Amen-Corner_, and
              _Ralph Smith_ at the _Royal-Exchange_, 1720.




[Illustration]




                                 TO THE

                            Right Honourable

                          _James Craggs_, Esq;

                                 ONE OF

                        His Majesties principal
                         Secretaries of State.

_SIR_,

I _Most humbly offer to You my Thoughts concerning the_ Prevention of
the Plague, _which I have put together_ _by your Command. As soon as you
was pleased to signify to me, in his_ Majestie's _Absence; that their
Excellencies the_ Lords Justices _thought it necessary for the Publick
Safety, upon the Account of the_ Sickness _now in_ France, _that proper
Directions should be drawn up to defend our selves from such a Calamity;
I most readily undertook the Task, though upon short Warning, and with
little Leisure: I have therefore rather put down the_ principal Heads of
Caution, _than a_ Set of Directions in Form.

The first, _which relate to_ the performing Quarentines, _&c. You, who
are perfectly versed in the History of_ Europe, _will see are agreable
to what is practised in other Countries, with some new Regulations_. The
next, _concerning the_ suppressing Infection here, _are very different
from the Methods taken in former Times among_ Us, _and from what they
commonly Do_ Abroad: _But, I persuade my self, will be found agreable to
Reason_.

_I most heartily wish, that the wise Measures, the_ Government _has
already taken, and will continue to take, with Regard to the_ former
_of_ these, _may make the_ Rules _about the_ latter _unnecessary:
However it is fit, we should be always provided with proper_ Means of
Defence _against so terrible an_ Enemy.

_May this short_ Essay _be received as one Instance, among many others,
of the Care, you always shew for Your Country; and as a_ _Testimony of
the great Esteem and Respect, with which I have the Honour to be,_

                                  SIR,

                          Your most obedient,
                          Most humble Servant,

Novemb. 25. 1720.

                                                                R. MEAD.

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                                PART I.

                                 OF THE

                                 NATURE

                                   OF

                              _CONTAGION_.

That the Reasonableness of any Method, which shall be proposed to
prevent the spreading of _Contagious_ Diseases, may the better appear,
it is necessary to premise somewhat in general concerning _Contagion_,
and the Manner, by which it acts.

Contagion is propagated by three Causes, the _Air_; _Diseased Persons_;
and _Goods transported from infected Places_.

We shall therefore first enquire what alteration of the _Air_ it is,
that makes it _infectious_; and then, by what Means it communicates its
noxious Quality to other Bodies.

The ancientest and best Authors of Physick, who lived in a Country more
exposed to these Calamities than ours, observed the Constitution of the
_Air_, which preceded _Pestilential Fevers_, to be great _Heats_
attended with much _Rain_ and _Southerly Winds_[1]: And one of Them
takes particular Notice, that no other than a _moist_ and _hot_
Temperament of the _Air_ brings the _Plague_; and that the Duration of
this Constitution is the Measure of the Violence of the Distemper[2].

The Natural History of several Countries confirms this Observation; in
_Africa_ particularly, if Showers fall during the sultry Heats of _July_
and _August_, the _Plague_ ensues thereupon, with which whosoever is
infected hardly escapes[3].

It has besides been remarked in all Times, that the Stinks of
_stagnating Waters_ in hot Weather, _putrid Exhalations_ from the Earth;
and above all, the Corruption of dead _Carcasses_ lying unburied, have
occasioned _infectious Diseases_.

From hence it appears to be a _Concurrence_ of Causes, that produces
Diseases of this Kind; which must not only meet, but exert their Force
together for a considerable time. And when this happens, their first
effect is a Degree of _Stagnation_ in the Air, which is afterwards
followed by _Corruption_ and _Putrefaction_.

And upon this account it is, that those Countries are chiefly liable to
these Calamities, where not only the _Heats_ are very great, and the
_Weather_ continues long in the same State; but the _Winds_ (the Use of
which is by Motion to purify the Air) do not shift and change so often
as they do in Northern Climates.

Indeed _Plagues_ seem to be of the Growth of the _Eastern_ and
_Southern_ Parts of the World, and to be transmitted from them into
colder Climates by the Way of _Commerce_. Nor do I think, that in this
_Island_ particularly there is any one Instance of a _Pestilential_
Disease among us of great Consequence; which we did not receive from
other _infected_ Places.

This I the rather mention, because it is a common Opinion, and
propagated by Authors of great Name, that we are usually _visited_ with
the _Plague_ once in 30 or 40 Years; which is a mere Fancy without any
Foundation either