An inaugural dissertation on the influenza : submitted to the examination of the Rev. John Ewing, S.T.P. provost ; the trustees and medical professors of the University of Pennsylvania, in order to obtain the degree of Doctor of Medicine, on the eighth day of May A.D. 1793 / by Robert Johnston, of Philadelphia, member of the American Medical Society.
- Johnston, Robert, 1750-1808
- Date:
- MDCCXCIII [1793]
Licence: Public Domain Mark
Credit: An inaugural dissertation on the influenza : submitted to the examination of the Rev. John Ewing, S.T.P. provost ; the trustees and medical professors of the University of Pennsylvania, in order to obtain the degree of Doctor of Medicine, on the eighth day of May A.D. 1793 / by Robert Johnston, of Philadelphia, member of the American Medical Society. Source: Wellcome Collection.
Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)
25/48
![In the fall of 1789, the influenza was very prevalent in the city of Philadelphia and its vicinity, and perhaps in many other parts of America. At that time I u as feized with it myfelf, and was fo ill as to be confined to bed for two days, neverthelefs, the remainder of the family, whicli confifted of fix perfons of different ages, and of both fexes, entirely efcaped every fymptom of the difeafe(23). Patrick RmTel, who refided many years at Aleppo, and who confequently had the beft opportunity oifeeing, and knowing what he relates, fays, that fome expofed every way to the infection [of the plague] as if invulnerable, remain found the whole feafon(24)- I am therefore decidedly of opinion with Doctor Cullen, that even the mofl powerful contagions do not operate, but when the bodies of men expofed to the contagion are in certain cir- tumftances, which render them more liable to be affected by it, or when certain caufes concur to excite the power of it(25). May we not, then, fafely conclude that there is required a certain ftate of the fyftem favourable to the action of the remote caufe, to render it capable of receiv- ing the infection ; and that this remote caufe of the in- fluenza may exift in the air, and yet every perion mail not be affected with this epidemic at the fame time, as the predifpofed ftate of the fyftem may not be prefent in every perfon at this particular time(26)« (23) To others, and thofe numerous, it was fo favourable as only to attack very few in each family. Lend.'Med. Trans. Vol. 3. Page 59. (24) Page ;o5. (2;) Firfl Lines, Volume the fecond, Page 2 16. (26) If the caufe lay in the air all muft have been feized at once hut as this was not found to be the cale, atld as tie clii- eafe appeared at different periods in different towns and villa- ires Doctor Hamilton infers that the caufe was contagion. But this is inferring too much ; for even from his own account of Harpenden, Luton, and St. Albans it eppears that at the firfl: D](https://iiif.wellcomecollection.org/image/b21133852_0025.jp2/full/800%2C/0/default.jpg)
