others; because what is thus critically thrown off by one, hath a Faculty of exciting the like Disorders in the Fluids of another, when it is insinuated into them; as a very small Quantity of some fermenting Substances will communicate its Efficacies a very great Way, and put very great Parcels of Fluid into the like Agitation. And this is the Way by which a malignant Fever comes to be infectious, and a Pestilence changes into a Contagion; as Bellini more largely explains it in his XXVIIIth Proposition of Fevers; from the whole of which it is manifest, as Dr. Mead hath expressed it in his fifth Essay of Poisons, that the Effects of the one are the Cause and Beginning of the other.
TO bring then this nearer to the Matter under Examination, the Plague which is described in the foregoing Pages, was strictly and properly a Contagion, and by all Accounts of the best Authority, That which hath made such vast Devastations in some Parts of France, and now continues to rage amongst them, to the great Terror of their Neighbours, is also of the same Kind; and was brought to them in Merchandize, and by a Ship’s Crew, who were sick of a pestilential
Disease all their Voyage Home from some Parts of Turkey; in neither of these there being any Manner of Fault chargeable upon the Air, or to any other Causes before enumerated in producing a Pestilence.
THE Symptoms of That now Abroad are reported by the best Physicians amongst them to be sudden Pains in the Head, great Loathing at Stomach, Reaching to Vomit, Consternation, wild Looks, trembling Voice, Coldness in the extreme Parts, low unequal Pulse, Paleness, Delirium, Convulsions, Carbuncles, Buboes, livid Vesications, purple Spots, and Hemorrhages; the last are certain Forerunners of Death. All which, more or less, are the constant Attendants of all pestilential Fevers.
BECAUSE then there is such a vast Difference between a Pestilence arising from assignable Causes in the Air, &c. and a Pestilence from a Contagion, as to the preservative Means especially against them; and that what we are now in most Apprehension of, is of the latter Kind; it most concerns us to be well acquainted with the Manner of Infection, as far as we can reason about Agents so extreamly minute and subtle. How all other Antecedents to a Pestilence exert
themselves in their Influences over the animal OEconomy, Bellini has brought even to a Demonstration; but as to a Contagion, he says little; which therefore, as introductory to some following Remarks, we shall here insert.
‘As this Coagulation and Fusion may go on so far as to set at Liberty, and perspire through the Surface of the Body, or with the Breath in Respiration, many noxious Particles, which may be so subtil and active, as to enter the cutaneous Pores of other Persons, or mix with that Air which they draw in Respiration, and when got into the Body, be able to make the same Change in the Blood, both as to its Coagulation and Fusion; hence it comes that such a Fever proves contagious, which is an inseparable Requisite to a pestilential Fever.
‘But this is not only thus brought about; but also the dissolved, and dispersed Particles may longer adhere to some inanimate Bodies than others, as to Woollen and Linen Cloaths, Papers, &c. and these Particles may, by the Steam of a living Body, or by the Means of any other Heat,
be put into Motion, so as to breath out of those Lodgments, where they quietly resided, and obtain so much Liberty, and Action on all sides, as will carry them into the cutaneous Pores of any Persons within their Reach, and infect them; and on this Account a Pestilence may be brought from very distant Countries, lying a long Time in such Manner concealed, and then suddenly breaking out; with many other Circumstances of like Nature.
‘BUT if these subtile and active Particles be of that Nature, that they can penetrate the Pores of other Animals, and occasion a like Coagulation of their Blood, not only Men, but Brutes also, will be seized with a Pestilence; but this does not always very necessarily happen; because the Blood of Animals is different from humane Blood, so that although these Particles are supposed to get into it, it does not therefore necessarily follow that they must vitiate it, any more than will Aqua Regia dissolve all kinds of Metals; but yet Brutes of all kinds, or some of them only, will be seized equally with Men, when this subtile and active Ferment, which penetrates the Surface, is of that