E-text prepared by K. Nordquist, Michael Roe, Carl Hudkins, and the Project Gutenberg Online Distributed Proofreading Team (http://www.pgdp.net) from page images generously made available by the Posner Memorial Collection, Carnegie Mellon University Libraries (http://posner.library.cmu.edu/Posner/) Note: Project Gutenberg also has an HTML version of this file which includes the original illustrations. See 29414-h.htm or 29414-h.zip: (https://www.gutenberg.org/cache/epub/29414/pg29414-images.html) or (https://www.gutenberg.org/files/29414/29414-h.zip) Images of the original pages are available through the Posner Memorial Collection, Carnegie Mellon University Libraries. See http://posner.library.cmu.edu/Posner/books/book.cgi?call=614.4_J54I_1798 AN _INQUIRY_ INTO THE CAUSES AND EFFECTS OF THE VARIOLAE VACCINAE. PRICE 7s. 6d. AN _INQUIRY_ INTO THE CAUSES AND EFFECTS OF THE VARIOLAE VACCINAE, A DISEASE DISCOVERED IN SOME OF THE WESTERN COUNTIES OF ENGLAND, PARTICULARLY _GLOUCESTERSHIRE_, AND KNOWN BY THE NAME OF THE COW POX. BY EDWARD JENNER, M.D. F.R.S. &c. ----QUID NOBIS CERTIUS IPSIS SENSIBUS ESSE POTEST, QUO VERA AC FALSA NOTEMUS. LUCRETIUS. London: PRINTED, FOR THE AUTHOR, BY SAMPSON LOW, No. 7, BERWICK STREET, SOHO: AND SOLD BY LAW, AVE-MARIA LANE; AND MURRAY AND HIGHLEY, FLEET STREET. 1798. TO _C. H. PARRY, M.D._ AT BATH. _My dear friend_, In the present age of scientific investigation, it is remarkable that a disease of so peculiar a nature as the Cow Pox, which has appeared in this and some of the neighbouring counties for such a series of years, should so long have escaped particular attention. Finding the prevailing notions on the subject, both among men of our profession and others, extremely vague and indeterminate, and conceiving that facts might appear at once both curious and useful, I have instituted as strict an inquiry into the causes and effects of this singular malady as local circumstances would admit. The following pages are the result, which, from motives of the most affectionate regard, are dedicated to you, by Your sincere Friend, EDWARD JENNER. Berkeley, Gloucestershire, June 21st, 1798. AN INQUIRY, _&c. &c._ The deviation of Man from the state in which he was originally placed by Nature seems to have proved to him a prolific source of Diseases. From the love of splendour, from the indulgences of luxury, and from his fondness for amusement, he has familiarised himself with a great number of animals, which may not originally have been intended for his associates. The Wolf, disarmed of ferocity, is now pillowed in the lady's lap[1]. The Cat, the little Tyger of our island, whose natural home is the forest, is equally domesticated and caressed. The Cow, the Hog, the Sheep, and the Horse, are all, for a variety of purposes, brought under his care and dominion.