THE Groans and unfeigned Tears of the Sick too plainly expressed the Aggravations of their Miseries, and some seemed even to drown their Sense of Pain with their Complainings; and this Intenseness of Pain cannot be a Wonder to any, who duly consider either the Nature of the pestilential Venom, or the Constitution of the Glands. I have already so largely discoursed of the Virulence and corrosive Qualities of the pestilential Poison, that no more need here be said about it; and whosoever examines the Glands will find, that from the great Distention of the Vessels, in this Case, the Buboes must chiefly owe their Rise to a Correspondence between the Nerves and Lymphaticks, and the Juices they contain. MANY Persons of publick Note have elegantly given the Anatomy and Use of the Glands; it is therefore sufficient for my Purpose here to shew, how from an Obstruction of those Juices, which flow through the larger Nerves, particularly of the Arms and Thighs, and their subservient Vessels, and their Impregnation with heterogeneous and poisonous Particles, Buboes do arise. IF any one makes it a Doubt, why these Tumors should rather come in the above-mentioned Places, rather than on the _parotide_ Glands, let such consider, that it is owing to the Magnitude and Capacity of the Nerves and Vessels constituting the Glands of those Parts; as also that their different Dispositions to Suppuration does proceed from the same Cause. BUT that this Affair may more fully appear, it is to be discovered from what Source that Matter flows, which degenerates into Matter, and discharges from a Buboe in so great Plenty. IN the Prosecution of this Enquiry, it shall not be without a Colour, at least, of Reason, that I shall dissent from an Opinion both of Ancients and Moderns, about the Blood alone being immediately changed into Matter; for I rather think it to proceed from other Juices; and this I shall endeavour to support by the following Arguments. AND first of all, notwithstanding the Blood which runs in the Arteries and Veins does sometimes, though very seldom, appear whitish; it then happens from too great a Mixture either of nutritious Juice, or of a degenerate Chyle, that will not easily change, and take its red Colour; but it never passes into Matter, because the necessary Conditions of Circulation will not admit of so much Rest as is requisite thereunto; besides, even the extravasated Blood will not easily undergoe such an Alteration: For when any Vessels, and chiefly the Capillaries, are so obstructed by Contusions, or any other Means, that the neighbouring Parts swell, every Physician and Surgeon too, I hope, knows that discutient Medicines and Cataplasms will restore the former Motion and Fluxility to the Blood, ease the Pain, and dissipate the Tumour.