[Decoration] AN ESSAY ON _Contagious Diseases_. [Decoration] AN ESSAY ON _Contagious Diseases_: More particularly On the _Small-Pox_, _Measles_, Putrid, Malignant, and Pestilential Fevers. By _Clifton Wintringham_. YORK: Printed by _Charles Bourne_ for _Francis Hildyard_, and are to be Sold by _W. Taylor_, at the Sign of the _Ship_ in _Pater-noster-Row_ LONDON, 1721. [Decoration] THE PREFACE. _The Design of this small Treatise being to deduce the Causes, and explain the_ Phoenomena _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_ Phoenomena, _'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._ York, _June 1st_. 1721. [Illustration] ERRATA. Page 8. Line 20. before Contagion insert _a Pestilential_. Page 52. Line 17. read _Buboes_. [Illustration] OF _Contagious Diseases_. [Decoration] CHAP. I. _Contagious Diseases_ are generally defin'd by Physicians to be such, as are capable of being communicated to us by the Air, or the Effluvia of Morbid Bodies. When the Cause producing these Diseases is general, and not occasioned by the peculiar Qualities of particular Places, but brought from Abroad, they are stiled _Epidemic_.