tag="{http://www.w3.org/1999/xhtml}a">[e] Piso Hist. Ind. & Brasil.

Several Causes of the Plague.

The other Observations of the Causes of these Fevers, may be reduced to such as arise from the Stinks of stagnating Waters in hot and close Weather, to some putrid Exhalations of the Earth, to the Parts of Animals and Vegetables putrifying in the open Air, or the taking of corrupt & unwholsome Nourishment.

Of the first kind was that at Selinis, occasioned by the stinking Exhalations of the stagnating Waters adjacent, which the discerning Empedocles removed by scouring its Ditches from their Filth, by a fresh Current of Water drawn from two Rivers in the neighbouring Country [g].

To the second Class may be reduced that Pestilential Fever, which the same great Philosopher check'd at Agrigentum, by stopping the Mouths of some neighbouring Mountains, whose pernicious Fumes had infected the adjacent Country [h]; As also that mentioned by Ammianus Marcellinus, which broke out in Seleucia, and over-ran a great Part of Greece, Italy, and Parthia, and took its Rise from the opening of an old Vault in the Temple of Apollo.

To the Third belong, such as are occasioned by the Parts of Vegetables and Animals, especially those of Men, putrifying in the open Air. As was that mention'd by Livy, which over-ran a great Part of Italy, and owed its Rise to the dead Bodies of the Romans and Fidenates left unburied in the Field of Battle [i]. Analogous to this was that which from the same Cause appeared in Germany, Anno 1630; And likewise that mentioned by Ambrose Parree from the same Cause; as also that mentioned by Diodorus Siculus, occasioned by great Quantities of Locusts driven by Winds into the Sea, and thence cast up in Heaps on the Shore. To this likewise must be reduced those Malignant and Pestilential Fevers, which so frequently attend Camps and Seiges, especially in the hot Eastern Countries, whose numerous Armies frequently feel the dismal Effects of these stinking Fumes: As do likewise the vast Caravans of the Mahometans in their Annual Pilgrimages to Mecca.

To the last belong those Pestilential Fevers, which take their Rise from a preceeding Famine, as was that in Judea in the time of Herod [k], in which the Product of the Ground being consumed by the great Heat, and long Drought of the preceeding Summer, the poorest sort of People were obliged, thro' the Scarcity of Provisions, to make use of such Food as afforded unwholesome and putrifying Juices.

CHAP. III.

The Changes wrought in the Animal Oeconomy from the above-mention'd Causes, may be reduced to such as depend either on the Increased Heat of the Air join'd with its Humidity; Or to such as are produced from the particular Qualities of the putrid and Contagious Particles floating in it; Or to the united and complicated Effects of all together.

Effects of a hot and moist Air.

The Alterations produced in the Body from a greater Heat continually surrounding it, provided it be not Excessive, are a Rarefaction of the Juices, and Relaxation of the Fibres on the Surface of the Body, and greater Derivation of the Fluids that way. Whence proceeds a large Evacuation of the perspirable Matter. This being continued in a greater Proportion than in a Natural State, will gradually deprive the Blood of its Aqueous and Spirituous Parts, and leave the remaining serous Part more stock'd with acrid and pungent Salts, and the Gross, Terrestrious, Oleaginous, and Viscous Particles more firmly united by their nearer Approach, and stronger Cohesion to each other. This greater Heat or Quantity of Fiery Particles, continually surrounding the Body, will necessarily insinuate it self into, and unite with the Saline, Sulphureous, and other Particles, in the same manner as we see it does with other Substances, both Solid and Liquid [l]; And likewise by increasing the Velocity of the Circulation and Attrition of the Particles against each other, render them on these Accounts also more Volatile, Pungent and Stimulating, and consequently the Blood will consist of Particles more gross and inspissated or coagulated, and likewise of those of a more acrid and pungent Disposition than in a natural State.

The Blood being in this