Where the cold paroxysm of an ague originates in the absorbents of the liver, spleen, or other internal viscus, the addition of steel to vegetable bitters, and especially after the use of one dose of calomel, much advances the cure.
And where it originates in any part of the secerning system, as is probably the case in some kinds of agues, the addition of opium in the dose of a grain and half, given about an hour before the access of the paroxysm, or mixed with chalybeate and bitter medicines, ensures the cure. Or the same may be effected by wine given instead of opium before the paroxysm, so as nearly to intoxicate.
These three kinds of agues are thus distinguished; the first is not attended with any tumid or indurated viscus, which the people call an ague cake, and which is evident to the touch. The second is accompanied with a tumid viscus; and the last has generally, I believe, the quartan type, and is attended with some degree of arterial debility.
[3]. This class of absorbent medicines are said to decrease irritability. After any part of our system has been torpid or quiescent, by whatever cause that was produced, it becomes afterwards capable of being excited into greater motion by small stimuli; hence the hot fit of fever succeeds the cold one. As these medicines prevent torpor or quiescence of parts of the system, as cold hands or feet, which perpetually happen to weak constitutions, the subsequent increase of irritability of these parts is likewise prevented.
[4]. These absorbent medicines, including both the bitters, and metallic salts, and opiates, are of great use in the dropsy by their promoting universal absorption; but here evacuations are likewise to be produced, as will be treated of in the Invertentia.
[5]. The matter in ulcers is thickened, and thence rendered less corrosive, the saline part of it being reabsorbed by the use of bitter medicines; hence the bark is used with advantage in the cure of ulcers.
[6]. Bitter medicines strengthen digestion by promoting the absorption of chyle; hence the introduction of hop into the potation used at our meals, which as a medicine may be taken advantageously, but, like other unnecessary stimuli, must be injurious as an article of our daily diet.
The hop may perhaps in some degree contribute to the production of gravel in the kidnies, as our intemperate wine-drinkers are more subject to the gout, and ale-drinkers to the gravel; in the formation of both which diseases, there can be no doubt, but that the alcohol is the principal, if not the only agent.
[7]. Vomits greatly increase the absorption from the cellular membrane, as squill, and foxglove. The squill should be given in the dose of a grain of the dried root every hour, till it operates upwards and downwards. Four ounces of the fresh leaves of the foxglove should be boiled from two pounds of water to one, and half an ounce of the decoction taken every two hours for four or more doses. This medicine by stimulating into inverted action the absorbents of the stomach, increases the direct action of the cellular lymphatics.
Another more convenient way of ascertaining the dose of foxglove is by making a saturated tincture of it in proof spirit; which has the twofold advantage of being invariable in its original strength, and of keeping a long time as a shop-medicine without losing any of its virtue. Put two ounces of the leaves of purple foxglove, digitalis purpurea, nicely dried, and coarsely powdered, into a mixture of four ounces of rectified spirit of wine and four ounces of water; let the mixture stand by the fire-side twenty-four hours frequently shaking the bottle, and thus making a saturated tincture of digitalis; which must be poured from the sediment or passed through filtering paper.