Decoctum Sarsaparillæ. L.E.D. See Sarsaparilla. In making this decoction, it is rarely properly digested or boiled for a sufficient length of time to extract its virtues. The only salts which occasion precipitates in this decoction are, nitrate of mercury and acetate of lead; lime water has the same effect. Dose, f℥iv to f℥vj.
Decoctum Veratri. Stimulant and acrid; internally, it is cathartic, but too violent to be safely exhibited; it is useful as a lotion in scabies, and other cutaneous eruptions.
2. Compound Decoctions.
Decoctum Aloes Compositum. It resembles the well known Beaume de vie, although less purgative, and is a scientific preparation, constructed upon the true principles of medicinal combination. Aloes is the base, to which are added, 1st, sub-carbonate of potass, 2ndly, powdered myrrh, 3dly, extract of liquorice, 4thly, saffron, and after the decoction is made, 5thly, compound tincture of cardamoms. By the 1st ingredient the aloes is rendered more soluble; the 2d and 3d suspend the portion not dissolved, and at the same time disguise its bitterness; the 4th imparts an aromatic flavour, and the 5th not only renders it more grateful to the stomach, but prevents any spontaneous decomposition from taking place. Its taste is improved by keeping. It is a warm, gentle cathartic. Form: 80. Dose, f℥ss to f℥j. Its operation is different from that of simple aloes. See Aloes. The following substances are incompatible with it; strong acids, oxy-muriate of mercury; tartarized antimony; sulphate of zinc; and acetate of lead; and those salts which are decomposed by sub-carbonate of potass.
Decoctum Guaiaci Compositum. E. Commonly called Decoction of woods. This decoction has fallen into disuse, and deservedly, for it can possess but little power, except, as a diluent, or demulcent; the water takes up from the guaiacum only a small portion of extractive matter, and the virtues of sassafras, if any, must be dissipated. Dose, f℥ss to f℥j.
Decoctum Hordei Compositum.[[490]] An elegant and useful demulcent, with an aperient tendency.
Decoctum Sarsaparillæ Compositum. L.D. This decoction, which is an imitation of the once celebrated Lisbon Diet Drink,[[491]] differs materially from the Decoct: Guaiaci comp: from the addition of the mezereon root, which renders it diaphoretic and alterative, and useful in the treatment of secondary syphilis, and chronic rheumatism. Dose, from f℥iv to f℥vj three or four times a day.
DIGITALIS FOLIA. L.E.D. (Digitalis Purpurea.)
Foxglove.
Qualities. The leaves, when properly dried, have a slight narcotic odour, and a bitter nauseous taste, and when reduced to powder, a beautiful green colour. Chemical Composition. Extractive matter, and a green resin, in both of which the narcotic properties reside; they appear also to contain ammonia, and some other salts.[[492]] Solubility. Both water and alcohol extract their virtues, but decoction injures them. Incompatible Substances. See Infusum Digitalis. Medicinal Uses. It is directly sedative, although some maintain the contrary opinion, diminishing the frequency of the pulse, and the general irritability of the system, and increasing the action of the absorbents, and the discharge by urine. The effects appear to be in a great degree connected with its sensible influence upon the body, which is indicated by feelings of slight nausea and languor; accordingly, every attempt to prevent these unpleasant effects, or to correct the operation of digitalis, by combining it with aromatic, or stimulant medicines, seems to be fatal to the diuretic powers of the remedy. Dr. Blackall, in his “Observations upon the cure of Dropsies,” has offered some remarks which bear upon this point, and to which I have before referred. See page 96 & 150.