3. I have observed one or more of the following symptoms, namely, head-ach; a decay, or increase of appetite; costiveness; a diminished or increased secretion of urine; a hot and offensive breath[14]; constant sweats, and sometimes of a f[oe]tid nature, or a dry skin; wakefulness, or a disposition to early or protracted sleep; a preternaturally frequent pulse; unusual vivacity, or depression of spirits; fatigue and sweats from light exertions; hands, when rubbed, emitting a smell like hepar sulphuris; and, lastly, a sense of burning in the mouth; to be present in different persons, during the prevalence of our malignant epidemics.
[14] I have once known this breath, in a gentleman who had carried the seeds of the yellow fever in his body from Philadelphia into its neighbourhood, create sickness at the stomach in his wife; and I have heard of an instance in which a person, who left Philadelphia when highly impregnated with the miasmata of the same fever, creating sickness at the stomach in four or five persons who sat at the same table with him in the country. None of the above persons were afterwards affected by the fever. In an anonymous history of the plague in London, in the year 1664, in the possession of the author, it is said, the breath was a well-known signal of infection to persons who were not infected, and that whenever it was perceived, individuals and companies fled from it. The sickness in the above-mentioned persons was similar to that which is sometimes excited by the smell of a sore leg, or a gun-shot wound, upon the removal of its first dressing. It does not produce fever, because there is no predisposition to it.
The means of preventing the different forms of our summer and autumnal disease come next under our consideration. I shall first mention such as have been most effectual in guarding against its malignant form, and afterwards take notice of such as are proper in its milder grades. These means naturally divide themselves again,
I. Into such as are proper to protect individuals.
II. Such as are proper to defend whole communities from the disease. And,
III. Such as are proper to exterminate it, by removing its causes.
I. Of the means of protecting individuals.