Part 2 (1/2)

IT is very plain, that animal Bodies are capable of being altered into a Matter fit to breed this Disease: because this is the Case of every one who is sick of it, the Humours in him being corrupted into a Substance which will _infect_ others. And it is not improbable, that the volatile Parts with which Animals abound, may in some ill States of Air in the sultry Heats of _Africa_ be converted by Putrefaction into a Substance of the same kind: since in these colder Regions, we sometimes find them to contract a greater Degree of Acrimony than most other Substances will do by _putrefying_, and also more dangerous for Men to come within the reach of their Action; as in those pernicious, and even poysonous Juices, which are sometimes generated in corrupted Carca.s.ses: Of which I have formerly given one very remarkable Instance[48], and, if it were necessary, many more might be produced, especially in _hydropic Bodies_, and in _cancerous Tumors_. Nay more, we find _animal Putrefaction_ sometimes to produce in these _Northern_ Climates very fatal Distempers, though they do not arise to the Malignity of the true _Plague_: For such _Fevers_ are often bred, where a large Number of People are closely confined together; as in _Goals_, _Sieges_, and _Camps_.

AND perhaps it may not be here amiss to remark, that the _Egyptians_ of old were so sensible how much the _Putridness_ of dead Animals contributed towards breeding the _Plague_, that they wors.h.i.+pped the Bird _Ibis_ for the Service it did in devouring great Numbers of Serpents; which they observed did hurt by their Stench when dead, as well as by their Bite when alive[49].

BUT no kind of _Putrefaction_ is ever hightened in these _European_ Countries to a degree capable of producing the true _Plague_: and we learn from the Observation of the _Arabian_ Physicians, that some Indisposition of the _Air_ is necessary in the hottest Climates, either to cause so exalted a Corruption of the forementioned Substances, or at least to enforce upon Mens Bodies the Action of the _Effluvia_ exhaled from those Substances, while they putrefy. Both which Effects may well be expected from the sensible ill Qualities of the _Air_ before described, whenever they continue and exert their Force together any considerable time.

WHAT I have here advanced of the first Original of the _Plague_, appears to me so reasonable, that I cannot enough wonder at Authors for quitting the Consideration of such manifest Causes for _Hidden Qualities_; such as _Malignant Influences of the Heavens_; _a.r.s.enical_, _Bituminous_, or other _Mineral Effluvia_, with the like imaginary or uncertain Agents.

THIS however I do not say with design absolutely to exclude all Disorders in the _Air_, that are more latent than the intemperate _Heat_ and _Moisture_ before mentioned, from a Share in increasing and promoting the Infection of the _Plague_, where it is once bred: for I rather think this must sometimes be the Case; like to what is observed among us in relation to another infectious Distemper, namely, the _Small-Pox_, which is most commonly spread, and propagated by the same manifest Qualities of the _Air_ as those here described: Notwithstanding which, this Distemper is sometimes known to rage with great Violence in the very opposite Const.i.tution of _Air_, _viz._ in the Winter during dry and frosty Weather. But to breed a Distemper, and to give force to it when bred, are two different things. And though we should allow any such secret Change in the _Air_ to a.s.sist in the first Production of the Disease; yet it may justly be censured in these Writers, that they should undertake to determine the _Specific Nature_ of these secret Changes and Alterations, which we have no means at all of discovering: Since they do not shew themselves in any such sensible manner, as to come directly under our Examination; nor yet do their Effects, in producing the _Plague_, point out any thing of their _Specific Nature_.

ALL that we know, is this, that the Cause of the _Plague_, whatever it be, is of such a Nature, that when taken into the Body, it works such Changes in the Blood and Juices, as to produce this Disease, by suddenly giving some Parts of the Humours such corrosive Qualities, that they either excite inward _Inflammations_ and _Gangrenes_, or push out _Carbuncles_ and _Bubo's_; the _Matter_ of which, when suppurated, communicates the like Disease to others: But of the manner how this is done, I shall discourse in the following Chapter.

CHAP. II.

_Of the Causes which spread the Plague._

I HAVE been thus particular in tracing the _Plague_ up to its first Origine, in order to remove, as much as possible, all Objection against what I shall say of the Causes, which excite and propagate it among us.

This is done by _Contagion_. Those who are Strangers to the full Power of _this_, that is, those who do not understand how subtile it is, and how widely the Distemper may be spread by _Infection_, ascribe the Rise of it wholly to the malignant Quality of the _Air_ in all Places, wherever it happens; and, on the other hand, some have thought that the Consideration of the infectious Nature of the Disease must exclude all regard to the Influence of the _Air_: Whereas the _Contagion_ accompanying the Disease, and the Disposition of the _Air_ to promote that _Contagion_, ought equally to be considered; both being necessary to give the Distemper full force. The Design therefore of this Chapter, is to make a proper Balance between these two, and to set just Limits to the Effects of each.

FOR this purpose, I shall reduce the Causes, which spread the _Plague_, to three, _Diseased Persons_, _Goods transported from infected Places_, and _a corrupted State of Air_.

THERE are several Diseases, which will be communicated from the Sick to others: and this not done after the same manner in all. The _Hydrophobia_ is communicated no other way than by mixing the morbid Juices of the diseased Animal immediately with the Blood of the sound, by a _Bite_, or what is a.n.a.logous thereto; the _Itch_ is given by _simple Contact_; the _Lues Venerea_ not without _a closer Contact_; but the _Measles_, _Small-Pox_, and _Plague_ are caught by a _near Approach_ only to the Sick: for in these three last Diseases Persons are render'd obnoxious to them only by residing in the same House, and conversing with the Sick.

NOW it appears by the Experiments mentioned in the _Preface_, of giving the _Plague_ to _Dogs_ by putting the _Bile_, _Blood_ or _Urine_ from infected Persons, into their Veins, that the whole ma.s.s of the animal Fluids in this Disease is highly corrupted and putrefied. It is therefore easy to conceive how the _Effluvia_ or Fumes from Liquors so affected may taint the ambient Air. And this will more especially happen, when the Humours are in the greatest Fermentation, that is, at the Highth of the Fever: as it is observed that fermenting Liquors do at the latter end of their intestine Motion throw off a great Quant.i.ty of their most subtile and active Particles. And this Discharge will be chiefly made upon those Glands of the Body, in which the Secretions are the most copious, and the most easily increased: such are those of the Mouth and Skin. From these therefore the Air will be impregnated with _pestiferous Atoms_: which being taken into the Body of a sound Person will, in the Nature of a _Ferment_, put the Fluids there into the like Agitation and Disorder.

THE Body, I suppose, receives them these two ways, by the _Breath_, and by the _Skin_; but chiefly by the former.

I THINK it certain that _Respiration_ does always communicate to the Blood some Parts from the Air: Which is proved from this Observation, that the same Quant.i.ty of Air will not suffice long for breathing, though it be deprived of none of those Qualities, by which it is fitted to inflate the Lungs and agitate the Blood, the Uses commonly ascribed to it. And this is farther confirm'd by what the learned Dr. _Halley_ has inform'd me, that when he was several Fathom under Water in his _Diving Engine_, and breathing an Air much more condensed than the natural, he observed himself to breath more slowly than usual: Which makes it more than probable, that this conveying to the Blood some subtile Parts from the Air, is the chief Use of _Respiration_; since when a greater Quant.i.ty of _Air_ than usual was taken in at a time, and consequently more of these subtile Parts received at once by the Blood, a less frequent _Respiration_ sufficed.

AS to the _Skin_, since there is a continual Discharge made thro' its innumerable _Pores_, of the matter of _insensible Perspiration_ and _Sweat_; it is very possible that the same Pa.s.sages may admit subtile Corpuscles, which may penetrate into the inward Parts. Nay it is very plain that they do so, from what we observe upon the outward Application of _Ointments_ and warm _Bathings_: which have their Effects by their finest and most active Parts insinuating themselves into the Blood.

IT is commonly thought, that the _Blood_ only is affected in these Cases by the morbific _Effluvia_. But I am of opinion, that there is another Fluid in the Body, which is, especially in the beginning, equally, if not more, concerned in this Affair: I mean the _Liquid of the Nerves_, usually called the _Animal Spirits_. As _this_ is the immediate Instrument of all Motion and Sensation, and has a great Agency in all the glandular Secretions, and in the Circulation of the Blood itself; any considerable Alteration made in it must be attended with dangerous Consequences. It is not possible that the whole Ma.s.s of Blood should be corrupted in so short a Time as that, in which the fatal Symptoms, in some Cases, discover themselves. Those Patients of the _first Cla.s.s_, mentioned in the beginning of this Discourse, particularly the _Porters_ who opened the infected Bales of Goods in the _Lazaretto_'s of _Ma.r.s.eilles_, died upon the first Appearance of Infection, as it were by a sudden Stroke; being seized with Rigors, Tremblings, Heart-Sickness, Vomitings, Giddiness and Heaviness of the Head, an universal Languor and Inquietude; the Pulse low and unequal: and Death insued sometimes in a few Hours.

EFFECTS so sudden must be owing to the Action of some Corpuscles of great Force insinuated into, and changing the Properties of, another subtle and active Fluid in the Body: and such an one, no doubt, is the _Nervous Liquor_.

IT is not to be expected that we should be able to explain the particular manner by which this is brought about. We know too little of the Frame of the Universe, and of the Laws of _Attractions_, _Repulsions_ and _Cohesions_ among the minutest Parcels of Matter, to be able to determine all the Ways by which they affect one another, especially within animal Bodies, the most delicate and complicated of all the known Works of Nature. But we may perhaps make a probable Conjecture upon the Matter. Our great Philosopher, whose surprising Discoveries have exceeded the utmost Expectations of the most penetrating Minds, has demonstrated that there is diffused through the Universe a _subtile_ and _elastic Fluid_ of great Force and Activity.

This he supposes to be the Cause of the _Refraction_ and _Reflection_ of the Rays of Light; and that by its _Vibrations_ Light communicates Heat to Bodies: and, moreover, that this readily pervading all Bodies, produces many of their Effects upon one another[50].

NOW it is not improbable that the _Animal Spirits_ are a thin Liquor, separated in the Brain, and from thence derived into the Nerves, of such a Nature that it admits, and has incorporated with it, a great Quant.i.ty of this _elastic Fluid_: which makes it a vital Substance of great Energy. And a Liquor of this kind must be very susceptible of Alterations from other active Bodies of a different Nature from it, if they approach to and are mixed with it: as we see some _Chemical Spirits_ upon their being put together, fall into a Fermentation, and make a Composition of a quite different kind.

IF therefore we allow the _Effluvia_ or _Exhalations_ from a corrupted Ma.s.s of Humours in a Body that has the _Plague_ to be volatile and firey Particles, carrying with them the Qualities, of those fermenting Juices from which they proceed; it will not be hard to conceive how these may, when received into the _nervous Fluid_ of a sound Person, excite in it such intestine Motions as may make it to partake of their own Properties, and become more unfit for the Purposes of the animal Oeconomy. But of this more in another Place.

THIS is one means by which the _Plague_, when once bred, is spread and increased: but the second of the forementioned Causes, namely, _Goods from infected Places_, extends the Mischief much wider. By the preceding Cause, the _Plague_ may be spread from _Person_ to _Person_, from _House_ to _House_, or perhaps from _Town_ to _Town_, tho' not to any great Distance; but this carries it into the remotest Regions. From hence the trading Parts of _Europe_ have their princ.i.p.al Apprehensions, and universally have recourse to _Quarantaines_ for their Security. The Universality of which Practice is a strong Argument, that _Merchandize_ will communicate _Infection_: for one cannot imagine, that so many Countries should agree in such a Custom without the most weighty Reasons. But besides, there is not wanting express Proof of this, from particular Examples, where this Injury has been done by several sorts of Goods carried from infected Places to others. Some of these I shall hereafter be obliged to mention; at present I shall confine my self to three Instances only. The _first_ shall be of the Entrance of the _Plague_ into _Rome_ in the Year 1656, which we are a.s.sured was conveyed thither from _Naples_ by Clothes and other Wares from that Place, brought first to Port _Neptuno_, and carried from thence to the Neighbouring Castle of St. _Lawrence_: which after having been kept some time there, were conveyed into _Rome_[51]. The _second_ Instance I shall take is from the Account given us of the Entrance of the Plague into _Ma.r.s.eilles_[52]; which being drawn up with great Exactness, may be the more rely'd on. It appears indisputably by this Account, that the Mischief was brought thither by Goods from the _Levant_. For the first, who had the Distemper, was one of the _Crew_ of the _s.h.i.+p_, which brought those _Goods_: the next were those, who attended upon the same _Goods_, while they were under _Quarantaine_; and soon after the _Surgeon_, whom the Magistrates of _Ma.r.s.eilles_ appointed to examine the Bodies of those, who died.

THIS Relation, if duly consider'd, is, I believe, sufficient to remove all the Doubts any one can have about the Power of _Merchandize_ to convey _Infection_: for it affords all the Evidence, the most scrupulous can reasonably desire. Possibly there might be some Fever of extraordinary Malignity in _Ma.r.s.eilles_, such as is commonly called _Pestilential_, before the Arrival of these Goods: But no such Fever has any indisputable Right to the t.i.tle of _Pestilence_, as I have before shewn. On the contrary, these two, the real _Pestilence_, and such _Pestilential Fevers_, must carefully be distinguished, if we design to avoid all Mistakes in reasoning upon these Subjects.

SOME such Fever of uncommon Malignity, I say, might perhaps be in _Ma.r.s.eilles_ before the Arrival of these Goods. There might likewise perhaps be an Instance or two of _Fevers_ attended with _Eruptions_, bearing some Resemblance to those of the _Plague_: for such I my self have sometimes seen here in _London_. But it is not conceivable, that there should be any Appearance of the true _Plague_ before that time: for it was full six Weeks from the time of the Sailor's Death, which had given the Alarm, and raised a general Attention, before the Magistrates received Information of any one's dying of the _Plague_ in the City.

And I believe it was never known, that the _Plague_, being once broke out, gave so long a Truce in hot Weather.

THE _Plague_, which has this present Year almost depopulated _Messina_, affords a _third_ Instance of the same kind. By an authentic Relation of it, published here[53] we are informed, that a _Genoese_ Vessel from the _Levant_, arrived at that City; and upon notice given that a Sailor, who had touched some Cases of _Cotton Stuffs_ bought up at _Patra.s.so_ in the _Morea_, where the Distemper then raged, was dead of the Plague, in the Voyage; the s.h.i.+p was put under _Quarantaine_: during which time the _Cotton Stuffs_ were privately landed. The Master and some Sailors dying three days after, the Vessel was burnt. These Goods lay for some time concealed, but were soon after publickly sold: upon which the Disease immediately broke out in that _Quarter_ where they were opened; and afterwards was spread through the whole City.