THE PREFACE.

The Design of this small Treatise being to deduce the Causes, and explain the Phœnomena of some of the most Fatal Diseases which afflict Mankind, can stand in Need of no Excuse, whatever the Performance it self may; and especially at a Time, when not only several of them Rage amongst us with uncommon Violence, but we are Daily threatned with the dreadful Calamity of a Raging Pestilence. I have endeavour'd to reduce these Diseases to the same Simplicity with Others, to speak Intelligibly of them, and show the real Changes in the Animal Oeconomy, from the Principles of the Modern Philosophy.

The Learned Authors who have already wrote on this Subject, have rejected this Part of it, as being so easie and obvious as to need no Explanation. I doubt not indeed but this is their Case: But how easie soever it may be to explain these Phœnomena, 'tis not every one, conversant in the Practice of Physick, that will give himself the trouble to deduce them; and 'tis for such chiefly that this small Tract is designed; to whom if it prove any way serviceable, I shall gain the End I proposed by it.

ERRATA.

Page 8. Line 20. before Contagion insert a Pestilential. Page 52. Line 17. read Buboes.

OF

Contagious Diseases.