Obs. The infusion of the Ph. E. being fully double as strong as that of the Ph. L. & D., must be taken in proportionate doses.
5. (Concentrated; Infusum rhei concentratum, L.)—a. Rhubarb (in coarse powder), 10 oz.; rectified spirit, 1 pint; cold distilled water, 1 quart; digest 10 days, with frequent agitation, then express the liquor, and filter it; or proceed by the method of displacement.
b. Rhubarb, 3 lbs. 5 oz.; cold distilled water, 11 pints; rectified spirit, 51⁄2 pints; as the last.
Obs. 1 fl. dr. of either of the above, added to 7 fl. dr. of water, forms 1 fl. oz. of liquid, resembling, and in many points preferable to, the infusion of the Ph. L. The above is the only way a fine, rich-coloured, and transparent concentrated preparation can be made, that will keep well. Should it not prove perfectly limpid, it may be clarified in the way already mentioned.
6. (Alkaline; Infusum rhei alkalinum, I. r. cum potassâ, L.—Copland.) Rhubarb, 2 dr.; carbonate of potassa, 1 dr.; boiling water, 1⁄2 pint; macerate for 4 hours, strain, and add of tincture of cinnamon, 1⁄2 fl. oz. In dyspepsia, acidity, heartburn, &c.
Infusion of Ro′ses. Syn. Infusum rosæ, L., 1. (Simple.) From the petals of red roses. Used as colouring and for a test; mixed with vinegar and sweetened with honey, it forms a popular gargle in sore throat.
2. (Compound; Infusum rosæ—Ph. E. I. rosæ compositum—Ph. L., I. r. acidum—B. P., Ph. D.) Prep.—a. Red rose petals (broken up), 1 oz.; dilute sulphuric acid, 1⁄2 oz.; boiling distilled water, 40 oz.; infuse for half an hour with the acid and water, and strain.—Dose, 1 to 2 oz.
b. (Ph. L.) Petals of the red or damask rose (dried and pulled asunder), 3 dr.; boiling water, 1 pint; mix, and add of dilute sulphuric acid, 11⁄2 fl. dr.; macerate for 2 hours, strain off the liquor, and dissolve in it white sugar, 6 dr. The Edinburgh form is nearly similar.
c. (Ph. D.) Petals, 2 dr.; boiling water, 1⁄2 pint; infuse 1 hour, strain, and add of dilute sulphuric acid, 1 fl. dr.
Obs. A vessel or glass of stoneware should be used to make the infusion in, as metallic vessels injure the colour of the liquid, and are also attacked by the acid. The best plan is to add the dilute sulphuric acid to the water before pouring it on the leaves. The infusion may be squeezed out of the leaves with the hands.