Epidemic..................................

That Summer Rush published his own 363-page opus on the epidemic:  An Account of the Bilious Remitting Yellow Fever, as It Appeared in the City of Philadelphia in the Year 1793.  He explained in the preface that it had been delayed "by the want of health" and that he had gone ahead and published it "under the great disadvantages, of having been hastily copied from my notes, amid frequent professional interruptions," only because the end of summer was fast approaching, and if the yellow fever returned, he wanted the nations's capital, and all American port cities, to have his account as a resource.

-Stephen Fried,  Rush:  Revolution, Madness & The Visionary Doctor Who Became A Founding Father

So, imagine you are the leading medical practitioner in a city of 50,000 and five thousand citizens die in a single summer from yellow fever.  Further, you have no idea of its actual cause (a virus spread by infected mosquitoes.  Please remember that the existence of viruses wasn't discovered for another hundred years), nor do you have any idea of a cure (there still isn't one).   Although he tried various concoctions, including the use of mercury chloride, purging and blood-letting were the main tools in his medicine bag.  It is a miracle more didn't die.