A Discourse on the Plague by Richard Mead (book recommendations website txt) 📖

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 Quantity 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 Mass 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 principal 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 assured 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 Marseilles[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 Ship, 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 Marseilles 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 Marseilles, such as is commonly called Pestilential, before the Arrival of these Goods: But no such Fever has any indisputable Right to the Title 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 Marseilles 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 Patrasso in the Morea, where the Distemper then raged, was dead of the Plague, in the Voyage; the Ship 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.

I think it not improper, for the fuller Confirmation of the present Point, to give a Relation communicated to me by a Person of unquestionable Credit, of the like Effect from Goods, in respect to the Small-Pox; which Distemper is frequently carried in the Nature of the Plague both to the East and West-Indies from these Countries, and was once carried from the East-Indies to the Cape of Good Hope, in the following manner. About the Year 1718, a ship from the East-Indies arrived at that Place: In the Voyage three Children had been sick of the Small-Pox: The foul Linen used about them was put into a Trunk, and lock’d up. At the Ship’s Landing, this was taken out, and given to some of the Natives to be washed: Upon handling the Linen, they were immediately seized with the Small-Pox, which spread into the Country for many Miles, and made such a Desolation, that it was almost dispeopled.

It has been thought so difficult to explain the manner how Goods retain the Seeds of Contagion, that some[54] Authors have imagined Infection to be performed by the Means of Insects; the Eggs of which may be conveyed from Place to Place, and make the Disease when they come to be hatched. But as this is a Supposition grounded upon no manner of Observation, so I think there is no need to have recourse to it. If, as we have conjectured, the Matter of Contagion be an active Substance generated chiefly from animal Corruption; it is not hard to conceive how this may be lodged and preserved in soft porous Bodies, which are kept pressed close together.

We all know how long a time Perfumes hold their Scent, if wrapt up in proper Coverings: And it is very remarkable, that the strongest of these, like the Matter we are treating of, are mostly animal Juices, as Mosch, Civet, &c. and that the Substances, found most fit to keep them in, are the very same with those, which are most apt to receive and communicate Infection, as Furrs, Feathers, Silk, Hair, Wool, Cotton, Flax, &c. the greatest part of which are likewise of the animal kind.

Nothing indeed can give us so just a Notion of Infection, and more clearly represent the manner of it, than Odoriferous Bodies. Some of these do strangely revive the animal Spirits; others instantaneously depress and sink them: We may therefore conceive that, what active particles emitted from any such Substances do, is in the like way done by Pestiferous Bodies; so that Contagion is no more than the effect of volatile offensive Matter drawn into the Body by our Smelling.

The third Cause we assigned for the spreading of Contagion, was a corrupted State of Air. Although the Air be in a right State, yet a sick Person may infect those who are very near him: As we find the Pestilence to continue sometimes among the Crew of a Ship, after they have sailed out of the Infectious Air wherein the Disease was first caught. A remarkable Accident of this Nature is recorded to have happened in the Plague at Genoa in the Year 1656. Eleven Persons put to Sea in a Felucca, with design to withdraw themselves from the Contagion, and retire into Provence; but one of them falling sick of the Plague soon after they had imbarked, infected the rest; insomuch that others being taken ill, and dying in their turns, they were not admitted any where, but were forced to return from whence they came: and by that time the Boat arrived again at Genoa no more than one of them survived[55].

However in this Case the Malady does not usually spread far, the contagious Particles being soon dispersed and lost. But when in a corrupt Disposition of the Air the contagious Particles meet with the subtile Parts generated by that Corruption, by uniting with them they become much more active and powerful, and likewise of a more durable Nature; so as to form an infectious Matter capable of conveying the Mischief to a greater distance from the diseased Body, out of which it was produced.

In general, a hot Air is more disposed to spread Contagion than a cold one, as no one can doubt, who considers how much all kinds of Effluvia are farther diffused in a warm Air, than in the contrary. But moreover, that State of Air, when unseasonable Moisture and want of Winds are added to its Heat, which gives birth to the Plague in some Countries, will doubtless promote it in all. For Hippocrates sets down the same Description of a Pestilential State of Air in his Country, as the Arabians do of the Constitution, which gives Rise to the Plague in Africa[56]. Mercurialis assures us the same Constitution of Air attended the Pestilence in his time at Padua[57]: and Gassendus observed the same in the Plague of Digne[58]. Besides, it is easy to shew how the Air, by the sensible ill Qualities discoursed of in the last Chapter,