"Since the middle of last July we have had a bilious colic epidemic in this neighbourhood, which exhibits phænomena very singular in this climate; and, so far as I am informed, unprecedented in the medical records, or popular traditions of this country. To avoid unnecessary details it will suffice at present to observe, that the disease, on this occasion, has assumed, not only all the essential characters, but likewise all the violence, obstinacy, and malignity described by the East and West-Indian practitioners. If any difference can be observed it seems here to manifest higher degrees of stubbornness and malignity than we usually meet in the histories of tropical writers. In the course of the disease, not only extreme constipation, frequent vomiting, and the most excruciating pains of the bowels and limbs, harass the unhappy patient; but to these succeed paralysis, convulsions, &c. and almost always uncommon muscular debility, oppression of the præcordia, &c. are the consequence of a severe attack. Bile discharged in enormous quantities constantly assumes the most corrupted and acrimonious appearances, commonly æruginous in a very high degree, and sometimes quite atrabilious. "The inference I mean to draw from the phænomena of this disease, as it appears in this neighbourhood, and which I presume will also apply to your epidemic, is _this_, that from the uncommon protraction and intenseness of our summer and autumnal heats, but principally from the unusual drought, we have had, since the middle of July, a near approach to a _tropical_ season, and that of consequence we ought not to be surprised if tropical diseases, even of the most malignant nature, are _engendered_ amongst us." To the above information it may be added, that the dysentery which prevailed during the autumn of 1793, in several of the villages of Pennsylvania, was attended with a malignity and mortality unknown before in any part of the state. I need not pause to remark that this dysentery arose from putrid exhalation, and that it is, like the bilious colic, only a modification of bilious fever. But further, a malignant fever, resembling that which was epidemic in our city, prevailed during the autumn in many parts of the United States, viz. at Lynn in Massachusetts, at Weatherfield and Coventry in Connecticut, at New-Galloway in the state of New-York, on Walkill and on Pensocken creeks in New-Jersey, at Harrisburgh and Hummelstown in Pennsylvania, in Caroline county in Maryland, on the south branch of the Potowmac in Hardie county, also in Lynchburgh and in Alexandria in Virginia, and in several counties in North-Carolina. In none of these places was there a suspicion of the disease being imported from abroad, or conveyed by an intercourse with the city of Philadelphia.