THE _French_ Physicians having distinguished the Sick at _Marseilles_ into five _Classes_, according to the Degrees of the Distemper, observed _Bubo's_, and _Carbuncles_, in all of them, except in those of the _first Class_, who were so terribly seized, that they died in a few Hours, or at farthest in a Day or two, sinking under the Oppression, Anxiety, and Faintness, into which they were thrown by the first Stroke of the Disease; having Mortifications immediately produced in some of the _Viscera_, as appeared upon the Dissection of their Bodies[17]. And this Observation of the _French_ Physicians, which agrees with what other Authors have remarked in former _Plagues_, fully proves, that these Eruptions are so far from being caused solely by the greater _Violence_ of this Disease, than of other Fevers, that they are only absent, when the Distemper is extraordinary fierce; but otherwise they constantly attend it, even when it has proved so mild, that the first Notice, the Patient has had of his Infection, has been the Appearance of such a _Tumor_: as, besides these _French_ Physicians, other Authors of the best Credit have assured us. From whence we must conclude, that these _Eruptions_ are no less a Specific Mark of this Disease, than those are, by which the _Small Pox_ and _Measles_ are known and distinguished. And as in the first _Class_ of those attacked with the Plague, so likewise in these two Distempers we often find the Patient to dye by the violence of the Fever, before any Eruption of the Pustules can be made. THIS Circumstance of the Plague being mortal before any Eruptions appeared, was attended with a great misfortune. The Physicians and Surgeons appointed to examine the dead Bodies, finding none of the distinguishing Marks of the Disease, reported to the Magistrates that it was not the _Plague_; and persisted in their opinion, till one of them suffered for his Ignorance, and himself, with part of his Family, dyed by the Infection: this Assurance having prevented the necessary Precautions[18]. AND this in particular shews us the difference between the true _Plague_, and those _Fevers_ of extraordinary Malignity, which are the usual Forerunners of it, and are the natural Consequence of that ill State of Air, we shall hereafter prove to attend all _Plagues_. For since all those Fevers, from which People recover without any Discharge by Tumors in the Glands, or by _Carbuncles_, want the _characteristic_ Signs, which have been shewn to attend the slightest Cases of the true _Plague_; we cannot, upon any just Ground, certainly conclude them to be a less Degree only of that Distemper: but as far as appears, they are of a different Nature, are not ordinarily _Contagious_ like the _Plague_, nor yet have any such necessary relation to it, but that such Fevers do sometimes appear, without being followed by a real _Pestilence_.