The Way by which _Bad Food_, _ill ripened Fruits_ of the Earth, _&c._ do oftentimes produce _Malignant_ and _Pestilential_ Diseases, is not very different from _That_ by which We have observ’d Unwholesome Airs to be the Cause of the like Effects. For the Juices with which Those do supply the Blood being Corrupted, must necessarily make a Fluid of quite other Properties than what the Animal Œconomy requires, that is, neither Fit for Nutrition, nor for the Secretion of those Liquors which in the several Organs are to be derived from It; whereupon the small _Tubes_ are obstructed by an unequally Glutinous _Slime_; and it is therefore no wonder, if besides the other Symptoms insuing, _Sore Pustules_, _Inflammations_, _Ulcers_, &c. (more common in Fevers from this Cause than in any other,) are raised in the Surface of the Body. This is the Ground of the common Observation, that a _Famine_ is very often succeeded by a _Pestilence_. And This _Calamity_ generally begins among the Poorer sort of People, whose Diet to be sure is the worst. The City of _Surat_ in the _East-Indies_ is seldom or never free from the Plague; and yet it is observ’d, that the _English_ who Trade there are in no danger of being Infected thereby. Now the Chief of the Natives in this Place are _Banians_, who neither Eat Flesh, nor Drink Wine, but Live very Poorly upon _Herbs_, _Rice_, _Water_, &c. and most of the Inhabitants do the like, except Foreigners; This Poor Fare, together with the Heat of the Climate, makes them so liable to Malignant Distempers; from the Attacks of which Those who Feed well are more Safe and Secure. * * * * * Thus much concerning _Poisonous Exhalations and Airs_, so far as the Consideration of the _Grotta de’ Cani_ has led Us on to enquire into their Effects; for tho’ there may be other Alterations of this same Element, differing in their Nature from this we have insisted upon, and yet equally Pernicious and Hurtful, yet We take no Notice of any of them, in regard that those which are from _Arsenical_, _Mercurial_, and the like _Fumes_, are reducible to a foregoing _Essay_; and those which are owing to a Change of the known Properties of the Air, may be easily explain’d by what has been already delivered in _This_. I shall therefore rather chuse to make some Remarks on the Mischief of another _Fluid_, which _as_ It is the next in use to This we have been treating of, _so_ the bad Qualities of it, when it comes to be altered, must necessarily be almost equally Fatal and Dangerous. I mean _Water_, which is of so constant Service, not only for our Drinks, but also in preparing of our Flesh and Bread, that it may justly be said to be the _Vehicle_ of all our Nourishment; so that whenever this happens to put on other Properties than are necessary to fit it for this Purpose, it is no wonder if in its Passage thro’ the Body these do make suitable Impressions there.