1793 Philadelphia yellow fever epidemic immune to the fever. Many of the slaves in Charleston in 1742 could have gained immunity before having been transported from Africa, by having been exposed to yellow fever in a mild case. People who survived one attack gained immunity. A total of 240 blacks died, in proportion to their population at the same rate as whites. Given the limited resources and knowledge of the times, the city's response was credible. The medical community did not know the natural history of yellow fever, a viral infection spread by the "Aedes aegypti" mosquito. Efforts to clean the city did not defeat
1793 Philadelphia yellow fever epidemic was also advocated by Dr. Edward Stevens, who in mid-September claimed it had cured Alexander Hamilton, Secretary of the Treasury, of the fever. Rush searched the medical literature for other approaches. Benjamin Franklin had given him letters sent by Dr. John Mitchell, related to treating patients during a 1741 yellow fever outbreak in Virginia. (Franklin never published the letters.) Mitchell noted that the stomach and intestines filled with blood and that these organs had to be emptied at all costs. "On this account," Mitchell argued, "an ill-timed scrupulousness about the weakness of the body is of bad consequences in these