A Cataplasm for the Feet.
Take Venice Treacle 2 ounces; Mustard Seed, Grains of Paradise, each 1 ounce and half; Bay Salt 1 ounce; black Soap 2 ounces; Oil of Spike 2 scruples; Vinegar a quantity sufficient, mix all.
That I may practically explain (according to my Notions) the several Kinds, manner of Operation, and rational use of Applications to the Feet; I say they act
I. By impressing a brisk touch on the Soles of the Feet; and the Cutis there be exquisitely sensible, the force of the Medicine is thence deriv'd on, to the minute Fibres, Membranes, Nerves, Brain and Spirits, and so, very readily to the Heart, Arteries and Blood. Of this kind, there are two sorts.
1. Those that are by Nature Quieting, and made actually Hot, as the Lotion for the Feet (which see) and they are used properly, when Blood being in an high Ebullation, Circulateth unequally, and rusheth impetuously into the superior Parts: As in burning hot Head Aches and Watchings.
2. Those that are Acrid, Stimulating as the Cataplasm of Herrings, and of Radish: And they are indicated when the Spirits being oppress'd (bur not exhausted and vanquish'd) grow Stupid and Sluggish as in Soporose Cases.
II. They act (not upon the Feet primarily, but) on the Spirits, by an immediate contact of the Particles sent off into the Blood. They are two sorts likewise.
1. Such as rouse up and expand, as Treacle, Garlick, Mustard, Euphorbium, &c. And these are requir'd where the Spirits are spent, and languish so extreamly, that not being able to make their Continuity and even Expansion, they fall into startings, tremblings and stoppings, as in Fevers, with twitchings of the Tendons and swooning Fits.
2. Such as pacify the enraged Spirits, as Pigeons and Chicken slit open alive, Lambs Lungs, &c. warm. And we use these, when the Spirits being vehemently irritated, fly into Explosions; as in pertinacious Watchings, Phrenzies, and Convulsions in Fevers.
Thomas Fuller
Pharmacopeia Extemporanea 1710