REVALEN′TA ARABICA. A mixture of the red Arabian or Egyptian lentil with barley flour, and a little sugar or salt. (‘Lancet.’) See Lentil and Revalenta.
REVERB′ERATORY FURNACE. See Furnace.
REVI′′VER. Prep. 1. (Black reviver, Paris’s anticardium.)—a. Blue galls (bruised), 4 oz.; logwood and sumach, of each 1 oz.; vinegar, 1 quart; macerate in a closed vessel, at a gentle heat, for 24 hours, then strain off the clear, add iron filings and green copperas, of each 1 oz., shake it occasionally for a week, and preserve it in a corked bottle.
b. Galls, 1 lb.; logwood, 2 lb.; boil for 2 hours in water, 5 quarts, until reduced to a gallon, then strain, and add of green copperas 1⁄2 lb. Used to restore the colour of faded black cloth.
2. (Blue reviver.) From soluble Prussian blue, 1 oz.; dissolved in distilled water, 1 quart. Used for either black or blue cloth.
RHAM′NIN. Prep. Express the juice from buckthorn berries scarcely ripe, which is to be rejected; boil the cake or residue with water, strain with pressure, and filter the liquid whilst hot; crude rhamnin will be deposited as the liquid cools, which, by solution in boiling alcohol and filtration, may be procured in crystals.
Obs. Buckthorn juice (succus rhamni), “the juice of the fruit of Rhamnus catharticus (Linn.),” is officinal in the Ph. L.
RHAT′ANY. Syn. Rhatany root; Krameriæ radix (B. P.); Krameria (Ph. L. E. & D.), Rhataniæ radix, L. “The root of Krameria triandria.” (Ph. L.) It is stomachic, and powerfully astringent and styptic.—Dose, 20 to 60 gr., either in powder or made into a decoction or infusion. It is
much employed in tooth powders, to fix the teeth when they become loosened by the recession of the gums, and also for improving the natural red colour of the lips and gums. A saturated tincture or fluid extract, made with brandy, forms the ‘wine-colouring’ used by the Portuguese to give roughness, colour, and tone to their port wine. Hard extract of rhatany is also much employed for the same purpose.
RHE′IN. Syn. Chrysophanic acid. The yellow colouring principle of rhubarb.