Nine books of physick and chirurgery written by that great and learned physitian, Dr Sennertus. The first five being his Institutions of the whole body of physick: the other four of fevers and agues: with their differences, signs, and cures.

CHAP. VII. Of the Nature of a Pestilent and Malignant Fever, and of the difference of them from the Plague.

FOrasmuch as the highest degree of corruption of humours is in the Pestilence, we must as it were ascend to it by the malignant and pestilent Fevers: of them therefore we will now speak, in what respect these three, the Pestilence, a pestilent and malignant Fever differ.

That the pestilence consists in a certain occult quality meerly adverse to mankind, and that it is infectious, * 1.1 and that a Fever is not of the same essence therewith, but yet commonly accom∣panies it, is already shewed: And therefore the Plague it self al∣so, when it hath a Fever joyned with it, may not without cause in some measure be called a pestilential Fever: yet other Fevers al∣so are called pestilent without the plague, wherein the corrupti∣on of humors hath not yet attained that high degree which may constitute the nature of venomous pestilence, yet they contain in them somwhat like to that venomous and malignant pesti∣lence, and moreover either are not pernitious, or contagious as the plague, if they are both of them, yet they are less destru∣ctive then the plague; for the difference of a pestilential Fever, so called in particular, and of the venomous pestilence (since the nature of them both is unknown) betrays it self in this, by the vehemency and contagiousness of it, which is perceived to be less, not only in sporadick Fevers, but in epidemical pestilenti∣als, then in the plague it self: But concerning malignant Fe∣vers, although they by a general name signifie truly pestilentials, yet in particular those are called malignant, wherein there is a less degree of corruption then in those that are truly pestilential, and wherein the humours which kindle the Fever contain in them some occult quality tending to venenosity; whence there is less destruction and infection, somtimes there is none.

And that the matter may be handled in few words, if it ap∣pear by the symptomes in any Fever, that besides putrefaction there is a lso some occult and maligne quality, and yet but few die thereof, whether they are epidemical Fevers, or sporadick, or

contagious, or not contagious; this is the first degree of corru∣ption, and such a Fever in particular is called malignant; but in case many die, and yet others are not infected, or although there be some contagion, and some destruction, and yet neither the contagion nor destructive power have attained to the highest degree, and many continue well in health, 'tis a pestilent Fever in particular. Lastly, if so be many which begin to be visited die, and that most every where are infected, and that the contagion be spread over remote places, 'tis the plague.

Notes

• * 1.1

  The plague pestilent and mali∣gnant Fe∣vers, how they differ.