is apt to sob, and to respire in a convulsive manner, for a short time. For the impression of the cold upon the lower limbs excites such vigorous vibrations in the abdominal and other muscles of expiration, as being nearer to the seat of the impression, than the muscles of inspiration, that a convulsive continued expiration is first produced, then a sob, or deep inspiration: and lastly, strong convulsive expirations and inspirations for some successions.
The good effects of cold bathing arise perhaps, in part, from its narrowing the sphere of attraction in the small parts of the muscular fibres, and at the same time making this attraction stronger. Hence it may be prejudicial in some paralytical affections, as it is found to be. For, if the small vessels of the nerves be obstructed, it may, by contracting the solids, increase the obstruction, and consequently, the impediment to the free vibrations necessary to sense and motion.
Twelfthly, Bathing in warm water, impregnated with active mineral particles, may, by exciting and increasing vibrations in the white medullary substance, as well as by other means, remove obstructions in its small vessels, and thus be serviceable in many paralytical disorders, as it is found to be in fact. The same reasoning is applicable to the stiffness, insensibility, and impotency, of motion, which the rheumatism often leaves in the limbs.
Cold bathing may in like manner be serviceable in paralytic and rheumatic disorders, by exciting and increasing vibrations; provided the ill effect from the immediate contraction do not preclude this good one.
Thirteenthly, Since frictions, and other impressions upon the skin, increase the vibrations there, it may be expected, that they should increase the heat. And this is the fact. If a person rub his hands together in cold weather, the sensation of heat will be felt to arise in a moment, and to go off again in a moment after he ceases to rub; for the vibrations excited by rubbing may be expected to languish immediately, if not kept up by continuing the friction.
Fourteenthly, Strong tastes may, according to the doctrine of vibrations, be expected to leave a heat upon the tongue, mouth, and fauces, as they are found to do. And, in general, all vivid impressions upon every part of our bodies ought to increase the heat generally or particularly; which perhaps is the case, though we are seldom able to determine this by observation.
Fifteenthly, All strong emotions of mind ought also to increase the heat of the body. This is a matter of common observation, if we except the chilliness of the skin, and coldness of the extremities, which have been explained above, agreeably to the doctrine of vibrations.
The three last articles favour the above delivered conjectures concerning the peculiar nature of the vibrations belonging to
