On the other Hand, it might be demonstrated, from the Nature of the Plague, that it is never, or very rarely, communicated from one Person to another. At present we will content our selves, to evince this Truth by a Demonstration of another kind, which is from Observation, or _à posteriori_, and I will borrow it too from Mr. _Graunt_, in his Observations on the Bills of Mortality. In his Observations on the [4]Plague of 1636: He says it lasted 12 Years, in eight whereof there died 2000 _per Annum_ one with another, and never under 800. The which shews, _That the Contagion of the Plague depends more upon the _DISPOSITION_ of the Air, than upon the _EFFLUVIA_ from the Bodies of Men_. Which also we prove by the sudden jumps which the Plague hath made, leaping in one Week from 118 to 927; and back again, from 993 to 258; and from thence again, the very next Week, to 852. The which Effects must surely be rather attributed to _Change_ of the _Air_, than of the _Constitutions_ of _Mens Bodies_, otherwise than as this depends upon that. [Footnote 4: Page 70.] And therefore as this very common Opinion, about the _Plague_ of _Pestilence_ passing from one Body into another, is not supported by any good Reason, far less by the _Suppositions_ and _Innuendo’s_ of Dr. _Mead_; and is now contrary to the best Observation, most duly and properly made, we may not doubt to declare, that it very rarely, and perhaps never, proceeds that Way. The _Third_ Way Contagion is spread, is, _by Goods transported from infected Places_. But the Reason of this Fact seems to surmount his Understanding, and no wonder, for it has already puzzled all other Philosophers and Physicians, insomuch, that it has driven them into absurd Notions of _Maggots_, against all Observation. But, before a Philosopher would spend his Time about this Difficulty, he should be sure his Fact is indisputably true, for thereby he may save himself much Trouble and Babling, about a Matter that is false in Fact. However, this Difficulty may have blunted the Edge of every other Genius, he makes no doubt to conquer it, and account for it to the World, as he now does in the following Words: _If, as we have conjectured, the Matter of Contagion be an active Substance, perhaps in the nature of a Salt, generated chiefly from the Corruption of a Human Body, it is not hard to conceive how this may be lodged and preserv’d in soft porous Bodies, which are kept pressed close together._