The root of Rheum officinale Baillon (nat. ord. Poly-gonaceae).

Habitat

Western and Central China.

Characters

In cylindrical, conical or flattish segments, deprived of the dark brown, corky layer, smoothish or somewhat wrinkled, externally covered with a bright yellowish-brown powder, marked with white, elongated meshes, containing a white, rather spongy tissue, and a number of short reddish-brown or brownish-yellow striae; compact, hard; fracture uneven; internally white, with numerous red, irregularly curved and interrupted medullary rays, which are radially parallel only near the cambium line; odor somewhat peculiar. aromatic; taste bitter, somewhat astringent.

Composition

The chief constituents are - (1) Chrysophan, C27H30O14, which yields Chrysophanic Acid, C15H10O4, about 3 per cent. Synonyms. - Rhein. Chrysarobin, see Chrysarobinum. It is not known whether, in the living plant, Rhubarb contains any Chrysophanic Acid, for when kept the Chrysophan quickly oxidizes to Chrysophanic Acid. The purgative properties are due to Ghrysophan which also gives the yellow color. (2) Erythroretin. (3) Emodin. (4) Phaeoretin. (5) Aporetin. (6) Rheotannic Acid,C26H26O14, to which the astringency of Rhubarb is due. (7) Lime Oxalate, 35 per cent., to which the grittiness is due.

Impurities

English Rhubarb; different taste, smell, and excess of starch. Turmeric, which is turned brown by Boric Acid.

Dose, 1 to 5 gr.; .06 to .30 gm. (stomachic); 10 to 30 gr.; .60 to 2.00 gm. (purgative).

Preparations

1. Extractum Rhei. - Extract of Rhubarb. By percolation with Alcohol and Water, and evaporation.

Dose, 3 to 5 gr.; .20 to 1.00 gm.

2. Extractum Rhei Fluidum. - Fluid Extract of Rhubarb. By maceration and percolation with Alcohol and Water, and evaporation. Fluid Extract of Rhubarb is used to make Mistura Rhei et Sodae and Syrupus Rhei.

Dose, 1/4 to 1 fl. dr.; 1. to 4. c.c.

3. Pilulae Rhei. - Pills of Rhubarb. Rhubarb, 20; Soap, 6 gm., to make 100 pills. Each pill contains 3 gr.; .20 gm. of Rhubarb.

Dose, 3 to 5 pills.

4. Pilulae Rhei Compositae. - Compound Pills of Rhubarb. Rhubarb, 13; Purified Aloes, 10; Myrrh, 6 gm.; Oil of Peppermint, 0.5 c.c., to make 100 pills. Each pill contains 2 gr.; . 13 gm. of Rhubarb. Dose, 1 to 3 pills.

5. Pulvis Rhei Compositus. - Compound Powder of Rhubarb. Synonym. - Gregory's powder. Rhubarb, 25; Magnesia, 65; Ginger, 10.

Dose, 1/2 to 1 dr.; 2. to 4. gm.

6. Tinctura Rhei. - Tincture of Rhubarb. Rhubarb, 100; Cardamom, 20; Glycerin, 100; Alcohol and Water to 1000; by maceration and percolation.

Dose, 1/2 to 1 fl. dr.; 2. to 4. c.c. (stomachic); 1 to 4 fl. dr.; 4. to 15. c.c. (purgative).

7. Tinctura Rhei Aromatica. - Aromatic Tincture of Rhubarb. Rhubarb, 200; Cassia Cinnamon, 40; Cloves, 40; Nutmeg, 20; Glycerin, 100; Diluted Alcohol, to 1000. By maceration and percolation.

Aromatic Tincture of Rhubarb is used to make Syrupus Rhei Aro-maticus.

Dose, 1 to 3 fl. dr.; 4. to 12. c.c.

8. Tinctura Rhei Dulcis. - Sweet Tincture of Rhubarb. Rhubarb, 100; Glycyrrhiza, 40; Anise, 40; Cardamom, 10; Glycerin, 100; Diluted Alcohol to 1000. By maceration and percolation.

Dose, 1/2 to 1 fl. oz.; 15. to 30. c.c.

9. Mistura Rhei et Sodae. - Mixture of Rhubarb and Soda. Sodium Bicarbonate, 35; Fluid Extract of Rhubarb, 15; Fluid Extract of Ipecac, 3; Spirit of Peppermint, 25; Glycerin, 350; Water to 1000. By solution.

Dose, 1/4 to 2 fl. oz.; 8. to 60. c.c.

10. Syrupus Rhei. - Syrup of Rhubarb. Fluid Extract of Rhubarb, 100; Potassium Carbonate, 10; Spirit of Cinnamon, 4; Glycerin, 50; Water and Syrup to 1000. By solution.

Dose, 1 to 4 fl. dr.; 4. to 15. c.c.

11. Syrupus Rhei Aromaticus. - Aromatic Syrup of Rhubarb. Aromatic Tincture of Rhubarb, 150; Syrup, 850. By mixture.

Dose, 1 fl. dr.; 4. c.c. for a child.