Between the time in which the body is thus wounded or injured, and the time in which the disease makes its appearance, there is an interval which extends from one day to six weeks. In the person who injured his toe by stumping it in walking, the disease appeared the next day. The trifling wound on the forehead which I have mentioned, produced both tetanus and death, the day after it was received. I have known two instances of tetanus, from running nails in the feet, which did not appear until six weeks afterwards. In most of the cases of this disease from wounds which I have seen, there was a total absence of pain and inflammation, or but very moderate degrees of them, and in some of them the wounds had entirely healed, before any of the symptoms of the disease had made their appearance. Wounds and læsions are most apt to produce tetanus, after the long continued application of heat to the body; hence its greater frequency, from these causes, in warm than in cold climates, and in warm than in cold weather, in northern countries.
II. Cold applied suddenly to the body, after it has been exposed to intense heat. Of this Dr. Girdlestone mentions many instances, in his Treatise upon Spasmodic Affections in India. It was most commonly induced by sleeping upon the ground, after a warm day. Such is the dampness and unwholesome nature of the ground, in some parts of that country, that "fowls (the doctor says) put into coops at night, in the sickly season of the year, and on the same soil that the men slept, were always found dead the next morning, if the coop was not placed at a certain height above the surface of the earth[48]." It was brought on by sleeping on a damp pavement in a servant girl of Mr. Alexander Todd of Philadelphia, in the evening of a day in which the mercury in Fahrenheit's thermometer stood at 90°. Dr. Chalmers relates an instance of its having been induced by a person's sleeping without a nightcap, after shaving his head. The late Dr. Bartram informed me, that he had known a draught of cold water produce it in a man who was in a preternaturally heated state. The cold air more certainly brings on this disease, if it be applied to the body in the form of a current. The stiff neck which is sometimes felt after exposure to a stream of cool air from an open window, is a tendency to a locked jaw, or a feeble and partial tetanus.