A meteor was seen at two o'clock in the morning, on or about the twelfth of September. It fell between Third-street and the hospital, nearly in a line with Pine-street. Moschetoes (the usual attendants of a sickly autumn) were uncommonly numerous. Here and there a dead cat added to the impurity of the air of the streets. It was supposed those animals perished with hunger in the city, in consequence of so many houses being deserted by the inhabitants who had fled into the country, but the observations of subsequent years made it more probable they were destroyed by the same morbid state of the atmosphere which produced the reigning epidemic.
It appears further, from the register of the weather, that there was no rain between the 25th of August and the 15th of October, except a few drops, hardly enough to lay the dust of the streets, on the 9th of September, and the 12th of October. In consequence of this drought, the springs and wells failed in many parts of the country. The dust in some places extended two feet below the surface of the ground. The pastures were deficient, or burnt up. There was a scarcity of autumnal fruits in the neighbourhood of the city. But while vegetation drooped or died from the want of moisture in some places, it revived with preternatural vigour from unusual heat in others. Cherry-trees blossomed, and apple, pear, and plum-trees bore young fruit in several gardens in Trenton, thirty miles from Philadelphia, in the month of October.
However inoffensive uniform heat, when agitated by gentle breezes, may be, there is, I believe, no record of a dry, warm, and stagnating air, having existed for any length of time without producing diseases. Hippocrates, in describing a pestilential fever, says the year in which it prevailed was without a breeze of wind[49]. The same state of the atmosphere, for six weeks, is mentioned in many of the histories of the plague which prevailed in London, in 1665[50]. Even the sea air itself becomes unwholesome by stagnating; hence Dr. Clark informs us, that sailors become sickly after long calms in East-India voyages[51]. Sir John Pringle delivers the following aphorism from a number of similar observations upon this subject: “When the heats come on soon, and continue throughout autumn, not moderated by winds or rains, the season proves sickly, distempers appear early, and are dangerous[52].”
Who can review this account of the universal diffusion of the miasmata which produced this disease, its universal effects upon persons apparently in good health, and its accumulation and concentration, in consequence of the calmness of the air, and believe that it was possible for a febrile disease to exist at that time in our city that was not derived from that source?
The West-India writers upon the yellow fever have said that it is seldom taken twice, except by persons who have spent some years in Europe or America in the interval between its first and second attack. I directed my inquiries to this question, and I now proceed to mention the result of them. I met with five persons, during the prevalence of the disease, who had had it formerly, two of them in the year 1741, and three in 1762, who escaped it in 1793, although they were all more or less exposed to the infection. One of them felt a constant pain in her head while the disease was in her family. Four of them were aged, and of course less liable to be acted upon by the miasmata than persons in early or middle life. Mr. Thomas Shields furnished an unequivocal proof that the disease could be taken after an interval of many years. He had it in the year 1762, and narrowly escaped from a violent attack of it this year. Cases of reinfection were very common during the prevalence of this fever. They occurred most frequently where the first attack had been light. But they succeeded attacks that were severe in Dr. Griffitts, Dr. Mease, my pupil Mr. Coxe, and several others, whose cases came under my notice.
I have before remarked that the miasmata sometimes excited a fever as soon as they were taken into the body, but that they often lay there from one to sixteen days before they produced the disease. How long they existed in the body after a recovery from the fever I could not tell, for persons who recovered were, in most cases, exposed to their action from external sources. The preternatural dilatation of the pupils was a certain mark of the continuance of some portion of them in the system. In one person who was attacked with the fever on the night of the 9th of October, the pupils did not contract to their natural dimensions until the 7th of November.
Having described the effects of the miasmata upon the body, I proceed now to mention the changes induced upon it by death.
Let us first take a view of it as it appeared soon after death. Some new light may perhaps be thrown upon the proximate cause of the disease by this mode of examining the body.
My information upon this subject was derived from the attendants upon the sick, and from the two African citizens who were employed in burying the dead, viz. Richard Allen and Absalom Jones. The coincidence of the information received from different persons satisfied me that all that I shall here relate is both accurate and just.