We all know how long a time _Perfumes_ hold their _Scent_, if wrapt up in proper Coverings: And it is very remarkable, that the strongest of these, like the _Matter_ we are treating of, are mostly _Animal_ Juices, as _Mosch_, _Civet_, &c. and that the Substances found most fit to keep them in, are the very same with those which are most apt to receive and communicate _Infection_, as, _Furrs_, _Feathers_, _Silk_, _Hair_, _Wool_, _Cotton_, _Flax_, &c. the greatest Part of which are likewise of the Animal Kind; which Remark alone may serve to lead Us a little into the true Nature of _Contagion_. From all that has been said, it appears, I think, very plainly, that the _Plague_ is a real Poison, which being bred in the Eastern or Southern Parts of the World, maintains it self there by circulating from _Infected_ Persons to Goods; which is chiefly owing to the Negligence of the People in those Countries, who are stupidly Careless in this Affair: That when the Constitution of the Air happens to favour Infection, it rages there with great Violence; That at that Time more especially diseased Persons give it to one another, and _Contagious Matter_ is lodged in Goods of a loose and soft Texture, which being packt up, and carried into other Countries, let out, when opened, the imprisoned Seeds of Contagion: And lastly, That the Air cannot diffuse and spread these to any great Distance, if Intercourse and Commerce with the Place infected be strictly prevented. [Illustration] [Illustration] PART II. OF THE METHODS TO PREVENT _CONTAGION_. As it is a satisfaction to know, that the _Plague_ is not a Native of our Country, so this is likewise an Encouragement to the utmost Diligence in finding out Means to keep our selves clear from It. This Caution consists of two Parts: _The preventing its being brought into our Island_; And, if such a Calamity should happen, _The putting a stop to its spreading among us_. The first of these is provided for by the established Method of obliging Ships, that come from _Infected_ Places, to _perform Quarentine_: As to which I think it necessary, that the following Rules be observed.