The London practice of physick, or, The whole practical part of Physick contained in the works of Dr. Willis faithfully made English, and printed together for the publick good.

CHAP. XI. Of the Malignant or Pestilential Fever in general.

BEsides the Continual Fever, such as above describ'd, and which arises by reason of some Principle in the Blood exalted too much, and disproportionate with the rest; there is another Species of it, which is raised by reason of the Blood being tainted with some venemous Miasm, and thereupon ready to incur various Coagulations and Corruptions; in which, not only the Spirit and the Sulphur, as in a Putrid Fever, make an exorbitant Effort, and force the Blood to boyl immoderately, but withal, the mixture of the Blood is forthwith dissolved, and its Liquor runs into parts; and so that horrible Symptoms, with a manifest danger of Life, are caused in this kind of Affect. Under this Rank we comprehend Malignant and Pestilential Fevers, the Plague, the Small Pox, and Measles; concerning which, it remains for us to treat at present.

By the unanimous Consent of all, the Force and Power of these Diseases are plac'd in a venemous Matter; because, upon a Pestilen∣tial Affect, even as upon drinking Poyson, we find that the Strength is suddenly cast down, and that Life is soon destroyed: and therefore, for explicating the nature of the Pestilence, it will not be amiss, first to enquire concerning Poyson in general, and after what manner it affects our Bodies; and then to shew what sort of Venom is disperst in the Plague and contagious Diseases: which being premitted, we shall speak in particular of the Affects even now mentioned.

We may justly give the name of Poyson to whatsoever sticking in our Body, violently and after a secret manner, injures the Temper and Actions of any part, or of the whole, destroys the Spi∣rits, or perverts their Motions, dissolves the mixture of the Liquors, causes Coagulations and Corruptions, subverts the Ferments and Fun∣ctions of the Viscera, and so on a sudden, and privily, endanger Life. There is a vast store of these in Nature, which are often engendred within our Bodies, and abundantly supply'd outwardly from the Earth, Air, and Water, and from the distinct Families of Minerals, Vegetables, and Animals.

As there is a great variety of Poysons, so there is no less a diversity of them, as to the Subjects, and the ways of their hurting; for, tho a great many poysonous things are said to be contrary to us, as to the whole Substance, so that they set upon any thing, and like a Funeral Flame, with a caustick Force reduce it, as it were, into Ash∣es: yet some of these, being endowed with a peculiar Force of of∣fending, rather hurt one Part or Substance than another. The Sub∣jects on which the Taint of the Venom fixes it self first of all, and most immediately, are two-fold, to wit, the Animal Spirits, or the spirituous and subtle Liquor passiing in the Brain and 'Genus Ner∣vosum, and the Blood flowing in the Heart and Vessels. When a dis∣proportionate Object presents it self to one of them alone, or to both together, so that thereupon the Crasis of the Liquors or of the con∣taining Parts, is subverted, whereby Functions necessary for perform∣ing the Offices of Life and Sense, are letted and this is done after a secret manner, and as it were on a sudden, these kinds of Effects we ascribe to Poyson.

The nervous Bodies, with the animal Spirit, are not set upon whol∣ly after the same manner by all sorts of Poysons; for sometimes they are assail'd with a Stupor, sometimes with Cramps and convulsive mo∣tions, and those of divers Kinds and Conditions. The Bite of the Tarantula causes a Dancing; the force transmitted from a Tortoise by a Spear, or the Cords of a Net, stupifies the hand of the Fisher; the Roots of Wild Parsnips, or the Seeds of Dranel, eaten, make Men tun mad; Opium, Mandrake, Henbane, and the like, cause a deep, and sometimes a mortal Sleep. These, and a great many other things, without any mighty Perturbation of the Blood, or Injury brought on the Heart, fast'n chiefly their Venom on the Animal Faculty or Spi∣rit.

There are also some Poysons which chiefly insinuate their Malignity into the mass of Blood; wherefore, after using some Medicines, a yel∣low or black Jaundice, sometimes a Leprosie, leprous Affects, or Swellings of the whole Body, are produc'd; Vapours rising from sub∣terraneous Vaults, also from Charcoals newly kindled, often suffoca∣ting the Vital Spirits, congeal the Blood withall, and stop its Motion; so that the Flame of Life cannot be continued in the Heart. Every Man may see how great a Corruption is communicated to the Mass of Blood from the pestilential Miasm, by the Spots and Pushes which are the infamous Marks, as it were, of the blasted Blood.

If the Injury first inflicted on either, viz. the ceconomy of the Heart or Brain be light, for the most part it is brought to an end with∣out any great Offence of either; wherefore, Convulsive Motions, a Stupor, Lethargy, Melancholy, Paralytick Affects, often begin with a landable Pulse, and without an immoderate Effervescence of the Blood; and afterward, if the Affect does not wax strong, they come

to an end, and cease by little and little. There are other Poysons which often deprave the Blood, and corrupt its Mixture by dissolving it, the animal Functions in the mean time continuing whole and sound; but if the Ferment of the Poyson be stronger, and lays deep∣er Roots, presently the Venom is disperst from the one into the Pro∣vince of the other; for when the nervous Parts are fill'd with a viru∣lent Juice, a Portion of the Venom, brought back with the nervous Latex, by the lymphatick Vessels into the Veins, is readily conveyed into the Mass of Blood, and defiles it with the Corruption prevailing in it: also from the Blood greatly infected with Venom, the Juice wherewith the Nerves are irrigated in a short time becomes tained; Hence, Persons that are mad are feverish, and such as are seiz'd with a pestilential Fever very often are assailed with a Delirium or Frenzy. Concerning these things, we must consider what kind of Alteration or Impression of Injury it is which is inflicted by Poyson on the Animal Spirits with the Brain and nervous Appendix; also what on the Blood, with the Heart and the Vessels annex'd to it.

As to the first, we observe, that that subtle Liquor, or the Animal Spirits, with which the nervous Bodies are influenced, and by the Expansion of which, Sense and Motion perform reciprocal Actions, are easily perverted from their Continuity, and even Expansion; for, the Nerves being of a sost Texture, and the Spirits wherewith they are fill'd being of a very subtle Substance, they are not able to endure any sorts of Objects that are strong or vehement; wherefore, when any violent or disproportionate Thing assails them by Surprise, they are often forc'd from their Expansion and Excursion, to a Flight and a Retreat, and often into Irregularities of motions; wherefore, sudden Passions of the Mind distract them, and stir them to Twitch∣ing and Convulsions: when the nutritive Juice wherewith they are supply'd is sent to them too sharp, acid, or austere, they undergo sometimes Resolutions, sometimes Shrinkings: and if some Object more contrary (such as we affirm Poyson to be) presents it self, whose Particles are of such a fierce Nature, or of such a Configuration, that they violently ferment with the nervous Liquor, they strongly drive the subtle or spirituous Part of it this way and that, or wholly drive it away; and either by their styptick Force they fix the rest of the Liquor, or force it by an Ebullition into disorderly Motions; Hence necessarily arise the evil Affects of the Brain and nervous Parts, viz. sometimes a Convulsion, a Trembling, a Shivering, sometimes a Stupor, or Resolutions, and other severe Symptoms. The Things which infect with Venom the nervous Juice after this manner, some∣times are gross, and only inflict their Injury when they are applyed in a very corporeal Substance; sometimes they are subtle, and being resolv'd into a Vapour, or even to a Breath, they disperse the Ferment of the Poyson from a little Point throughont the whole Genus Nervo∣sum.

Sometimes the Poyson of an ill Thing eaten first begins its Tragedy in the Stomach, but oftner by a bare Contact on the Surface of the Body, it leaves the virulent Miasm, which soon and readily de∣files, with its Ferment, the Spirits dispers'd through the whole. A Taint inflicted on the Extremities of the Nerves, any where, whether inwardly or outwardly, it dispers'd to a distance by their ready Con∣veyance, presently many Sprouts of the same Branch being brought to communicate of the Evil. Often, a light Touch of a venemous Thing by the Finger, or the extream part of any Member, presently conveys the Taint received to the Brain, and thence it is retorted on the whole Body, and the most remote Members: the Reason of this is, that the Particles both of the nervous Juice, and of some venemous Miasm, are so active and quick of Motion, that either of them pass most swiftly through the whole Mass of the others, as Rays of Light through a Diaphanous Medium.

2. As often as the Blood gets Mischief by a venemous Thing, the Venom sticking in it, either is dull and of less Activity, which does not presently discover it self, nor breaks forth into terrible Symptoms, till after a long time, when it is brought to a Ripeness by a tacit Fer∣mentation, and has first infected the whole Mass of Blood; as we may observe in some Poysons, which are said to kill at a distance, and not but after some Months or Years: or the Poysons inspired into the Blood are imbued with a much sharper Sting, that the Taint con∣tractef by their Contagion presently breaks forth into terrible Symp∣toms; and thereupon follows sometimes a feverish Effervescence, with a Vomiting, a Thirst, and a burning of the Praecordia; sometimes a puffing up of the whole, a discolouring of the Skin, often an Erup∣tion of Pushes and Buboes; frequently also a sudden falling of the Strength, so that a sudden Death steals on without any Stir, and al∣most unperceiv'd: where it is to be noted by the By, if the Spirits of the Blood provok'd by the Enemy, are able to set upon him and to contend for the Victory, from this Conflict a feverish Ebullition is rais'd in the Blood; but, if the Particles of the Poyson far exceed them in Strength, presently the Mase of Blood is corrupted, that it can neither be circulated in the Vessels, nor be duely kindled in the Heart.

If it be farther enquired, what Changes in its Substance, or Consi∣stency, the Blood infected with Poyson undergoes, that thereby it is rendred unfit for the Support of Life; I answer after this manner, Some Poysons fuse the Blood, and precipitate its Serosity, as those Medicines which being destructive either by Purging, or by causing a Flux of Urine, or by a puffing up of the whole, or by a Discolourati∣on, or an Eruption of Pushes, make a very great Separation of the Serous Latex: mean while, a great ebullition is caused in the mass of Blood, whereby the Vital Spirits are greatly spent; the Particles of

the Salt and Sulphur, by the too much Contion, are exalted, and of∣ten so scorch'd, that a Jaundise, either yellow or black, is caused.

There are Poysons of another kind far more dangerous, which con∣geal the Blood, and corrupt its mixture by destroying it, viz. first they bring a Coagulation on the Mass of Blood, and then a Corrupti∣on; for, when the Spirits of the Blood, put to flight by the Contagi∣on of the Poyson, are dissipated, the even mixture of the Liquor is dissolved; wherefore, the grosser Particles mutually lock with each other, and (like Milk upon Rennets being put into it, or turning soure of its own accord) they are coagulated together; hence the Blood grows clotted in the Vessels, that it is not readily circulated in them: the coagulated Portions of it being convey'd inwardly into the Sinus's of the Hearts, are there apt to stagnate, and so they cause frequent Faintings and Swoonings: being carried outward, and stuck in the Skin in circulating, sometimes, when cast on every side in a plentiful manner, they cause an over-spreading of Blackness throughout the whole; sometimes being disperst more spartingly, they cause only Spots, or black and blew Marks, and the rest of the Phoenomena of Malignity: now the Coagulation of the Blood soon disposes it to Pu∣trefaction or Corruption, as it is to be seen in extravasated Blood, which soon turns black, and is wont to putrefie; for the Spirit being exhal'd the remaining Particles of the Salt and Sulphur in the Blood begin to separate from each other, and to dissolve the Bond of Mix∣ture, whence Putrefaction ensues.

These things being thus premitted concerning Poyson in general, the method of Healing requires that we set upon the Tract of Fevers, which draw their Origine wholly from a venemous and malignant Miasm: and since among these, the Plague is undoubtedly the chief, I shall be∣gin with the Consideration of that, and shall speak afterward, in order, of Malignant Fevers, the Measles, and Small-Pox. But before I give its Definition, I shall enquire briefly concerning the Pestilential Venom, of what Nature and Disposition it is; also whence it arises; and lastly, after what manner it is propagated by Contagion in others.

The Essence of the Pestilential Fever is founded in a vapory and spiritual Miasm, from which Effluvia's diffused on every side so pow∣erfully display themselves, that from the least Seminary they soon propagate a fertile Harvest of Death and Destruction. By reason of its mighty Activity, this Miasm deserves to be called, a certain Quin∣tescence, as it were, of Poyson: its very nimble and subtle Particles penetrate all Bodies, and inspire them with their Ferment; for, whe∣ther being dispers'd through the Air, or stored up in some Fomes, if they come to hit upon a Homane Body, tho it be lightly, and as it were, with a Glance, they readily penetrate it, soon infect the Ani∣mal Spirits and those of the Blood, and thereby overspread all the Members with a Venemous Contagion.

When a pestilential Breath or Vapour has assailed any one, and that Venom has first seiz'd the Animal Spirits, or those of the Blood, or both of them together; from the subtle and thin Substance of these the Taint is soon derived into the grosser Matter, for in a short time it ferments the whole Mass of Blood, or nervous Juice, and the excre∣mentitious Homours in any place abounding; and thence is drawn in∣to the solid Parts, and fixes the Evil in them. If this Contagion first seises the Animal Parts, presently the Injury is communicated to the Brain, and the Genus Nervosum, and esecially to the Ventricle; it forthwith poysons the Homour lodging in these, dissolves its mixture, perverts its regular Motion, and renders it wholly disagreeing and of∣fensive to the tender substance of the containing Parts: thence forth∣with Cramps, and Convulsive Motions, violent Vomitings, a Cardialgia, also a Frenzy, Delirium, or obstinate Watchings, are raised about the first Invasion of the Disease; whereas in the mean while, the Taint being not yet disperst through the Blood, the Diseased are not in a Fever, nor infested with a disorderly, Pulse, or a Swooning, or an ap∣pearance of Tokens; which Symptoms, nevertheless, assoon as the Blood is infected, shew themselves afterward. If at any time the Spirits of the Blood are first seised with the venemous Miasm, either breathed in with the Air, or attracted by the Pores, by and by its ferment is disperst throughout the whole mass of Blood, the infected portions presently begin to be loosned from their even mixture, to se∣parate into parts, and to be coagulated, and the same being conveyed into the Sinus's of the Heart, to stagnate there, and to cause a Swoon∣ing, Faintings, and often a sudden Death: also being carried outward∣ly, and fixt about the Skin, they are wont to cause Bubo's, Pushes, and the other marks of a Venenosity, mean while the Diseased are present enough to themselves, and are not assail'd with a Delirium or convul∣sive Motions: but if from a stronger cause an Injury be inflicted on both Parts at once, the course of the Disease is carried on with a more horri∣ble appearance of Symptoms, and with a Phrensy infesting together.

As to what regards its rise; when the Plague first arises in any Region or Tract of the Earth (whatsoevre others may think) we place the first and chief natural Seminary of this Poyson in the Air, for it seems consonant to reason, that from the same Fountain from whence the Food of common Life is derived, the beginnings also of Death, which is no less diffused, should be taken: the same necessity lies upon us for breathing the Air, as for Fish of living in the Waters; where∣sore, as the common Destruction of Fish dying in Multitudes is as∣cribed to Waters being infected with Poyson, so nothing but a Taint of the Air, breathed by all, can kill Men that dye without a manifest Cause, by an epidemick Destruction.

For the Air, which we necessarily breath in for the Support of Life, consists of thick Steams and Vapours, which continually are breathed

from the Earth; to which the exhalations of Salts and Sulphurs being mixed, they make here a thick Fog, as it were, of Atomous Corpus∣cles. The Motions of these being both very swift and restless, are of a manifold and very differing Figure; wherefore some of them con∣tinually encounter others, and according to their various Configurati∣ons, they close with these and are mutually combined, and are driv'n and fly from others: on this the Reasons of every Sympathy and Anti∣pathy chiefly depend; from the divers Agitations of these kinds of Atomes near the Surface of the Earth, this or that Tract of the Air undergoes divers Alterations, with which Bodies, especially those that are living, are variously affected, for the inward Motion of the Particles of each Animal depends very much on the motion and temper of the Particles of the Air: Since these continually exagitate those, stir them up when they are drowsie, repair the Losses of those that fly away, exa∣gitate the vital Flame with their Nitrosity, and supply it with a nitro∣sulphureous Food, and eventilate it being kindled by the continual Courses of Accesses and Recesses: as long as an apt Contemperation happens for the Motion and Configuration in both, Animals enjoy a perfect Life and Health; but if the Corpuscles flying in the Air are of such a kind of Figure and Power, that they are manifestly contrary to the Spirits implanted in Animals, they loosen the mixtures of these from the rest of the Elements with which they are bound, and per∣vert their Motions: hence the Crases of things are destroyed, Life is overthrown, and that being scarce extinct, the Bodies incur Putrefa∣ction; hence the Tops of Trees or Corn being struck with a Blast wither on a sudden; hence the Murrain oftentimes reigns amongst Cattel, which kills whole Herds together. For this kind of Cause the Seeds of the Pestilence first exert themelves, and threaten a uni∣versal Slaughter of Mankind; for even as venemous Corpuscles gather∣ed together in the Bowels of the Earth, or on its Surface, produce Ar∣senical Mixts, or venemous Herbs; so these being resolved into a Va∣pour, and gathered thick together in the Air, create pernicious Blasts, from which malignant and pestilential Diseases arise: and it seems to me not improbable, that the things which first give a seminary of the Pestilence to any peculiar Tract of the Air, are the venemous Effluvia of Salts and Sulphurs grown exorbitant, and breath'd forth of the Bow∣els of the Earth; which sometimes, being first long included in the Earth, are exhal'd by degrees; sometimes, by reason of Tremblings of Openings of the Earth, break forth together; of which kind also there are generally breath'd from the Tents of Souldiers filled with Nastiness, by reason of dead Carcasses lying unburied, or from places fill'd with staguating and stinking Mud. And Corupscles exhaled after this manner, by a long Putrefaction, acquire to themselves won∣derful Powers and Discongruencies, that thereby they are disagreeing and heterogeneous to all others whatsoever; and so being received in∣to

to the Air, they ferment it (like a mass of Liquor) and pervert it from a'wholsome and benign into a pernicious and curst Nature.

Some Bodies easily receive the malignant Tincture of a pestilential Air, others not so readily; those who have a very great Cacochymia by reason of an ill Dyet, and those who by reason of a Plethora have a Blood filled with an inflamable Sulphur, a light Blast of a venemous Air fastens the pestilential Venom on them, especially if they lye un∣der a Fear and Sadness, which convey inwardly the lightest Parts of Contagion, as it were by a certain Infusion. On the contrary, those who have the Viscera clean, and the Mass of Blood well tempered, and those who carry a strong and undaunted Mind, do not so eafily receive this Infection; and sometimes being receiv'd they expell it again.

So far of the Pestilence and its Communication, according to its first Being, and the Source of the infected Air thence drawn; it remains for us to speak of its Propagation by Contagion, as it is often commu∣nicated from some Men to others, as it were ex traduce.

By Contagion we understand that Force, or Action, whereby any Affect being in one Body stirs up the like to it in another; but since this happens either immediately by Contact, as if any one lying in the same Bed with another Man seiz'd with the Plague, gets the same Dis∣ease; or mediately, and at a distance, as if it happens that the Conta∣gion be convey'd from one House to others at a distance; and so if the Plague assails any Person handling a Garment or Houshold-stuff of an infected House, after some Days, or Months, or haply Years: tghere∣fore, that the nature of a Contagion, and the divers manners of it, may be plainly known, let us examine first, What that things is which flows from an infected Body: secondly, How it is fisposed in the me∣dium through which it passes: thirdly, After what manner it engen∣ders an Affect like it self in another Body.

1. That from every Body, though of a fixt Nature, Effluvia's of Atoms constantly flow, which make, as it were, a mist or cloudy Cir∣cle about them, and invest them, as it were, like the Down of a Peach, it is so receiv'd a thing among the soundest Philosophers, that there is nothing more; and the more active Particles any thing consists of, by so much it sends from it Corpuscles of a more notable Vertue, and Energy: hence the Effluvia which part from Electrick Bodies, are albe to move other Bodies from their Places; from Sulphurs Emana∣tions pass, which fill the whole Neighbourhood with Odours: since therefore the pestilential Venom, as is said before, tho in a small Bulk, is of a mighty Efficacy and Operation, wheresoever it is fixt, certain Emanations necessarily proceed from the Bodies imbued with it, which carry the nature of the same Poyson and Malignity, and diffuse it on every side according to its Sphere of Activity: but since these Corpus∣cles which retain the Contagion of the Pestilence, when they flow from

one body, are not presently received by another, let us inquire how they are disposed in respect of their passing through the Medium.

Where presently occurrs the difference of them from most others, in regard that the Effluvia, which generally evaporate, do not long retain the Nature of the body whence they flow, but either vanish in the tenuated Air, or closing with other bodies, are assimilated with them: but those Particles which part from a pestilential Miasm, are not easily absorb'd by the Air, or other Body, so that they wholly pe∣rish; but among various Consusions of Atomes, and Dashings against other bodies, they preserve themselves entire: for this Poyson being ina manner masterless, and insuperable by others, continues still the same; and tho it consists of a very small heap of Atomes, it does not presently vanish, but taints with its Ferment the next Corpuscles to it, and so acquires to it self new Stores, and gets Strength as it goes; whence it lies long hid in every Fomes, and after a long time, when it has lighted on a fit Subject, it exerts it self, and communicating the Infection of its Venom to the other, it resuscitates a-new the Disease of the Plague, which before seemed to be driv'n away, and tho from a very small Seminary, it disperses its mortal Povson far and near.

For the Plague discloses such most certain Signs of its Contagion, that some Authors affirm it to subsist among Mortals only by this means, and that it not where arises a-new, but is preserv'd only by a Fomes, and that it is now and then conveyed from one Region into another. Histories tell us, that the Seeds of it have lain dormant for many Years in a Garment or Bed-Cloaths, that upon the same after∣ward being stirr'd, they have shewn themselves, and have brought the Disease of the Pestilence, arising a-fresh, with a mighty Destruction of Mankind: when by reason of a Fomes the Pestilence is propagated to a distance after this manner; the venemous Corpuscles which remain in the Miasm, being stirred, presently spring forth, and display their Venom on every side, as it were by a certain Irradiation: if they any where light on a humane Body, they presently seise the Spirits, and are conveyed inward by their Vehicle, and then easily enough infect the Blood, and all other Homours flowing in the Vessels with their Ferment, and in a short time cause Coagulations and a Putrefaction in them. And after this manner, by most subtle Effiuvia, there is made a certain Transmigration, as it were, of the pestilential Disease, ev'n as when a graft cut from some Tree, and laid aside for some time, and afterward inserted in another Trunk, is able, though from a very small Bud, to produce a Tree of the same Kind and Nature.