The principal period groups were digitalis preparations, squill, broom, juniper oil, buchu, nitrous ether spirit, and several soluble potassium salts. They were grouped by observed promotion of urine flow, rather than by one common mechanism. The following are historical adult quantities per administration, expressed in the contemporary units; they are not present-day prescriptions.
Other recognised period agents included dandelion and copaiba. The dandelion decoction was given in quantities of 1–2 fluid ounces, its soft extract in quantities of 10–30 grains, and its preserved juice in quantities of ½–2 fluid drachms. Copaiba was given in quantities of 15–30 minims, and copaiba oil in quantities of 5–20 minims. Their historical inclusion does not establish that they are suitable substitutes for current diuretic therapy. [ref]
The distinction between preparations matters more than a single “dose of the plant”: an infusion, tincture, juice and powder have different concentrations. Likewise, a salt's small historical diuretic dose is not its larger purgative dose. A modern explanation also separates a direct effect on renal tubules from improved cardiac output in appropriate heart failure: digitalis preparations cannot be understood simply as agents that make every kidney excrete more water. Modern digoxin is used for selected cardiac indications, rather than as a general treatment for low urine output. [ref]
The compositions must be specified ingredient by ingredient; the two alkaloidal solutions contain 4 grains per nominal fluid ounce, but one contains a morphine salt and the other strychnine.
Pulvis Jalapae Compositus contains powdered jalap 5 avoirdupois ounces, potassium hydrogen tartrate 9 avoirdupois ounces, and powdered ginger 1 avoirdupois ounce. Thus the mass proportions are 5:9:1, and jalap supplies one third of the powder's mass. This is a compound purgative, not pure jalap resin. [ref]
Pilula Scillae Composita contains powdered squill 1¼ avoirdupois ounces, powdered ginger, ammoniacum and hard soap 1 avoirdupois ounce each, with treacle 2 avoirdupois ounces, or sufficient to make a pill mass. Using the specified 2 avoirdupois ounces of treacle, the whole is 6¼ avoirdupois ounces and contains one fifth squill by mass. The allowance of sufficient treacle makes consistency a compounding requirement, not a claim that every moist pill batch has an analytically exact 20% squill content. [ref]
Liquor Strychniae contains strychnine 4 grains, dilute hydrochloric acid 6 minims, rectified spirit 2 fluid drachms and distilled water 6 fluid drachms. Dissolve the strychnine in the acid mixed with part of the water, using the prescribed assistance of heat, then add the spirit and remaining water. Its conventional strength is ½ grain of strychnine per fluid drachm. Acid promotes solubility by forming a soluble salt of the alkaloid. [ref]
For the last two solutions, the stated historical strengths use the nominal 8 fluid drachms of spirit and water. The extra few minims of dilute acid must still appear in the actual recipe; treating all ingredient volumes as perfectly additive would not give an exact modern analytical concentration.