AS the People of _Marseilles_, from the first Foundation of their City by the _Phoceans_, were famous for Trade, and made long Voyages Southwards on the _African_ Coast[38]; so they have in all times been very liable to the Plague. A French Author[39] in a History of the late Plague at _Marseilles_ reckons up twenty Plagues that have happened in that City; notwithstanding it is by its situation one of the most healthy and pleasant Places in _France_, and the least subject to epidemic Distempers. But if we had no Records of this in History, an odd Custom among them, mentioned in Antiquity[40], of the way they made use of to clear themselves from this Distemper, would be a proof of it. Their manner at such times was, that some one poor Man offered himself to be maintained at the publick Expence with delicate Food for a whole Year: at the end of which he was led about the City dressed in consecrated Garments and Herbs; and being loaded with Curses as he went along, that the Evils of the Citizens might fall upon him, he was at last thrown into the Sea[41]. AGREEABLE to this Remark upon Trade is the Observation of _Procopius_ in his forecited History, that the _Plague_ was always found to spread from _Maritime_ Places into the _Inland_ Countries: which has ever since been confirmed by Experience. HAVING shewn this Disease to be a Distemper of a distinct Species, and to take its Rise only in _Africa_; we must next seek for its Cause in that Country and no where else. We ought therefore to consider, what there is peculiar to that Country, which can reasonably be supposed capable of producing it. Wherefore I shall briefly set down as much as serves for this purpose of the State of _Grand Cairo_ in _Egypt_, and of _Æthiopia_, the two great Seminaries of the _Plague_: Travellers relating that these Countries are more infested with it than most other Parts of _Africa_. _GRAND CAIRO_ is crouded with vast Numbers of Inhabitants, who for the most part live very poorly, and nastily; the Streets are very narrow, and close: it is situate in a sandy Plain at the Foot of a Mountain, which by keeping off the Winds, that would refresh the Air, makes the _Heats_ very stifling. Through the midst of it passes a great _Canal_, which is filled with Water at the overflowing of the _Nile_; and after the River is decreased, is gradually dried up: Into this the People throw all manner of Filth, Carrion, _&c._ so that the Stench which arises from this, and the Mud together, is insufferably offensive[42]. In this Posture of things, the _Plague_ every Year constantly preys upon the Inhabitants; and is only stopt, when the _Nile_, by overflowing, washes away this Load of Filth; the _Cold Winds_, which set in at the same time, lending their Assistance, by purifying the Air.