BUT least I should be thought too prolix in the Enumeration of such Circumstances, and incur the Suspicion of Atheism, (a Charge too just upon the Faculty) by ascribing too much to second Causes, as the Schools please to call them, it may be convenient for me to declare, that the το θειον of a Pestilence is as much a Part of my Faith, as any others; the sacred Pages clearly and demonstratively prove, that the Almighty, by his Authority, and at his Pleasure, may draw the Sword, bend the Bow, or shoot the Arrows of Death; and a Retrospection into Times past, shews many convincing Proofs of this terrible Truth; and in this Contagion before us, the Footsteps of an over-ruling Power are very legible, especially so far as concerns his divine Permission: But the great God’s Purposes are Secrets too awful for Mortals to pry into, although we know that he punishes as a Parent, and chides for our Good, which makes it our Duty to kiss the Rod, and submit. But enough of this, least I should be thought to invade anothers Province; and it is sufficient to the Purpose of a Physician, to assign natural and obvious Causes; and where such are discoverable, it is unworthy of him and the divine Art he professes, as well as an Affront to good Sense, to have Recourse to any other. BUT this being premised only to prevent Censure, our Way now lies open to a Discovery of the Nature of this Pestilence. Wherein, for Method Sake, I shall begin with a Description of a Pestilence in general; and which if it doth not exactly agree with the Accounts given by the Ancients, yet I doubt not but it will be found by every impartial Considerer, to be as full and satisfactory. THE Pestilence is a Disease arising from an _Aura_ that is poisonous, very subtle, deadly, and contagious, affecting many Persons at the same Time together in one Country, chiefly arising from a Corruption of the nitrous Spirit in the Air, attended with a Fever, and other very grievous Symptoms. EVERY one of these Particulars are as clear as the Light at Noon-day; and these Explications are so obvious to be met with in the Writings of the Learned, that it would be lost Labour to insist upon any such Thing here; we shall therefore proceed to explain only what more immediately stands in need of it. AND first of all it is said from an _Aura_, as distinguishing it from such Poison as is more gross and earthy; for this is not to be confined in any Inclosure, but is so rare, subtle, volatile, and fine, that it insinuates into, and resides in the very Interstices, or Pores of the aerial Particles; whereas that which is of a more fixed Nature, is confined within certain Limits, and is incapable of such Progress.