BUT in order to this Inquiry, it will be convenient, in the first place, to remove an erroneous Opinion some have entertained, that the _Plague_ differs not from a _common Fever_ in any thing besides its greater Violence. Whereas it is very evident, that since the _Small-Pox_ and _Measles_ are allowed to be Distempers distinct in _Specie_ from all others, on account of certain Symptoms peculiar to them; so, for the same reason, it ought to be granted, that the _Plague_ no less differs in Kind from ordinary Fevers: For there are a Set of distinguishing Symptoms as essential to the _Pestilence_, as the respective Eruptions are to the _Small-Pox_ or _Measles_; which are indeed (as I have mentioned in the Preface) each of them _Plagues_ of a particular kind. AS the _Small-Pox_ discharges itself by _Pustules_ raised in the Skin; so in the _Plague_ the noxious Humour is thrown out either by _Tumors_ in the Glands, as by a _Parotis_, _Bubo_, and the like; or by _Carbuncles_ thrust out upon any part of the Body. And these Eruptions are so specific Marks of this Distemper, that one or other of them is never absent: unless through the extreme Malignity of the Disease, or Weakness of Nature, the Patient sinks, before there is time for any Discharge to be made this way; that Matter, which should otherwise have been cast out by external _Tumors_, seizing the _Viscera_, and producing _Mortifications_ in them. SOMETIMES indeed it happens, by this means, that these _Tumors_ in the _Glands_, and _Carbuncles_, do not appear; just as a bad kind of the _Small-Pox_ in tender Constitutions sometimes proves fatal before the _Eruption_, by a _Diarrhoea_, _Hæmorrhage_, or some such Effect of a prevailing Malignity.