heat. The phænomena enumerated in all the fifteen may admit of other explanations, at least in part, but of none, as far as I can judge, that are inconsistent with the doctrine of vibrations.
The manifest solution of continuity, which is the very essence of a wound, may occasion pain, agreeably to the doctrine of vibrations, in the manner that has been explained already. This is the immediate pain that attends a wound. The subsequent one is to be referred either to the head of inflammation, or to that of ulcer.
The immediate pain from burns has likewise been explained agreeably to the doctrine of vibrations, also the separation of the dead or mortified eschar, under the last proposition. The subsequent pain is to be referred to the heads of inflammation and ulcer, as before.
A bruise is supposed, and with the appearance of reason, to be an infinite number of infinitely small wounds. It ought therefore to be attended with a pain resembling that of a large wound, and yet not exactly the same, which is the fact. As large wounds are sometimes healed by the first intention, without any subsequent ulcer, so may bruises. If otherwise, the subsequent pain must again be referred to the heads of inflammation and ulcer.
Lacerations are great wounds attended with bruises, i.e. with an infinite number of infinitely small ones. These are never cured without coming to digestion, i.e. an ulcer, and the requisite previous inflammation.
The heat and distention of the small vessels in inflammations are sufficient to account for the pain attending them, upon principles already laid down.
In ulcers the nerves are exposed defenceless, and therefore are susceptible of the most violent vibrations, and consequent pain from slight impressions: to which it is to be added, that the moisture of ulcers, by dissolving the saline parts of bodies applied, greatly augments their actions upon the naked nerves.
Fomentations and cataplasms seem to afford relief in the foregoing cases, partly by diffusing an equal warmth all around, partly by their aqueous or oily moisture. For the diffusion of warmth prevents that conflict, which would arise between neighbouring parts of different heats; and the moisture, which insinuates itself among the small particles, sets them at greater distances, and consequently lessens their mutual actions. The violent vibrations will therefore be moderated on both accounts. The friction attending embrocations does in like manner diffuse vibrations all around, and the liniment or liquid, with which the
