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.
On the other hand, I would not be understood to call every Fever a Plague, which is followed by Eruptions resembling these here mentioned: For as every Boil or Pustule, which breaks out upon the Skin, is not an Indication of the Small Pox, nor every Swelling in the Groin a Venereal Bubo; so there are Carbuncles not Pestilential, and other Fevers, besides the Plague, which have their Crisis by Tumors and Abscesses, and that sometimes even in the Parotid or other Glands. There is indeed usually some difference between these Swellings in the Plague, and in other Fevers, especially in the time of their coming out: for in the Plague they discover themselves sooner than in most other Cases. But the principal difference between these Diseases, is, that the Plague is infectious, the other not; at least not to any considerable Degree.
And this leads me to another Character of this Disease, whereby it is distinguished from ordinary Fevers, which is the Contagion accompanying it. This is a very ancient Observation. Thucydides makes it a part of his Description of the Plague at Athens[19]; and Lucretius, who has almost translated this Description of Thucydides, dwells much upon it[20]. Aristotle makes it one of his[21] Problems, How the Plague infects those who approach to the Sick. And what is of more Consequence, Galen himself is very clear in it[22]; for he has these words: ὅτι συνδιατρίβειν τοῖς λοιμώττουσιν ἐπισφαλὲς, ἀπολαῦσαι γὰρ κίνδυνος, ὥσπερ ψώρας τινὸς, &c. that it is unsafe to be about those, who have the Plague, for fear of catching it, as in the Itch, &c. Indeed this is a thing so evident, that we find it at present the current Opinion of all Mankind, a very few Persons only excepted, who have distinguished themselves by their Singularity in maintaining the opposite Sentiment. And it is something strange that any one should make a Question of a thing so obvious, which is proved sufficiently by one Property only of the Disease, that whenever it seizes one Person in a House, it immediately after attacks the greatest part of the Family. This Effect of the Plague has been so remarkable at all times, that whoever considers it well, cannot possibly, I think, have any Doubt remaining, or require any stronger Argument to convince him, that the Disease is infectious. For this very reason the Small-Pox and Measles are generally allowed to be contagious; because it is observed, that when either of these Diseases is got among a Family, it usually seizes successively the greatest part of that Family, who have not had it before: at least if such in the Family hold free Communication with the Sick. And by the same Argument the Plague must be concluded to be infectious likewise. It cannot be pretended, that this is occasioned in the Plague from this only, that the sound Persons are render’d more than ordinarily obnoxious to the unhealthy Air, or whatever be the common Cause of the Disease, by being put into fear and dispirited, upon seeing others in the same House taken sick: For if this were the Case, Children, who are too young to have any Apprehensions upon this Account, would escape better than others, the contrary of which has been always experienced.
It is true, some have not been attacked by the Disease, though constantly attending about the Sick. But this is no Objection against what is here advanced: for it is as easily understood how some Persons, by a particular Advantage of Constitution, should resist Infection, as how they should constantly breath a noxious Air without hurt. An odd Observation of Diemerbroek deserves notice in this Place; That, part of a Family removed into a Town free from the Plague, was observed by him to be taken ill of it soon after the part left behind in the diseased Town fell sick: which certainly could scarce have happened, unless a Communication between the Healthy and the Sick, by Letters or otherwise, was capable of causing it[23]. Of the same Nature is a Circumstance recorded by Evagrius of the Plague, which he describes, and what, he owns, surprized him very much: That, many of those, who left infected Places, were seized with the Plague in the Towns to which they had retired, while the old Inhabitants of those Towns were free from the Disease[24]. But to multiply Proofs of a thing so evident, is needless; innumerable are at hand, and several will occasionally occur in the following Parts of this Discourse, when we come to speak in particular of the ways, by which this Infection is conveyed about. I shall therefore say no more in this Place, but only, that all the Appearances attending this Disease are very easily explained upon this Principle, and are hardly to be accounted for upon any other. We learn from hence the reason why when the Plague makes its first Appearance in any Place, though the Number of Sick is exceeding small, yet the Disease usually operates upon them in the most violent manner, and is attended with its very worst Symptoms. Now was the Disease produced not by imported Contagion, but from some Cause, which had its Original in the diseased Place, and consequently from a Cause gradually bred, the contrary must happen: the Diseased would at first not only be few in Number, but their Sickness likewise more moderate than afterwards, when the morbific Causes were raised to their greatest Malignity. From the same Principle we see the reason, why People have often remained in Safety in a diseased Town, only by shutting themselves up from all Communication with such, as might be suspected of giving them the Disease. When the Plague was last in England, while it was in the Town of Cambridge, the Colleges remained entirely free by using this Precaution. In the Plague at Rome in the Years 1656 and 1657, the Monasteries and Nunneries, for the most part, defended themselves by the same Means[25]: Whereas at Naples, where the Plague was a little before, these Religious Houses, from their Neglect herein, did not escape so well[26]. Nay the Infection entered none of the Prisons at Rome[27], though the Nastiness of those Places exposes them very much. But, to avoid Prolixity, I shall give only one Instance more. I think it cannot be explained in any other reasonable manner, how the last Plague in the City of London, which broke out in the parish of St. Giles’s in the Fields towards the latter end of the Year 1664, should lie a-sleep from Christmas to the middle of February, and then break out again in the same Parish; and after another long rest till April,
