Fig. 99. - Chinese rhubarb: transverse section.

(best, most expensive - orange color, agreeable odor), "Canton" (smoky odor, bitter, ochre-yellow), "Shanghai" (smoky odor, light yellow; exported chiefly from Canton, occasionally via India; 3, European (Rhaponticum - R. palmatum, R. rhaponticum, R. compactum, R. undulatum, R. Emodi +), cultivated in England, France, Austria (Moravia), the rhizome being cut to resemble the Chinese, but differing in having the outside nearly or entirely without white meshes, the medullary rays interrupted, narrow, nearly straight, with paler color, weaker odor, and less gritty but more mucilaginous taste; rarely imported.

Constituents. - Resin, Aloe-emodin, Chrysophanic acid, rhein, emodin, emodin monomethyl ether, rheinolic acid (new anthraquinone derivative), volatile oil, rheotannic acid, gallic acid, cinnamic acid, palmitic acid, stearic acid, oleic acid, linolic acid, verosterol (phyto-sterol), dextrose, levulose, calcium oxalate 2-40 p. c. (the greater the amount, the greater the activity of the drug, the two going hand in hand); starch, ash 12-13 p. c. - very inferior 35-45 p. c.

Resin. - Chief purgative principle; amorphous, non-glucosidic - obtained from alcoholic extract, after removing volatile oil, by separating from greenish-yellow residue in still the dark aqueous liquid, extracting it with ether, then with amyl alcohol, evaporating to get brown tarry liquid and yellowish granules, crystals (aloe-emodin, chrysophanic acid, rhein, emodin, emodin monomethyl ether, rheinolic acid - all of which the resin yields upon hydrolysis); evaporate brown tarry filtrate, dissolve in alcohol and precipitate with equal quantity of chloroform.

Aloe-emodin and Chrysophanic Acid. - Both slightly purgative, obtained by concentrating above ethereal liquid, heating residue with ethyl acetate, adding petroleum, decanting from tarry precipitate, evaporating petroleum solution, dissolving in ether, extracting with 10 p. c. aqueous solution of sodium carbonate (aloe-emodin), or with 10 p. c. aqueous solution of potassium hydroxide (chrysophanic acid). Aloe-emodin is the rhabarberon and iso-emodin of some writers.

Preparations. - 1. Extractum Rhei. Extract of Rhubarb. (Syn., Ext. Rhei., Powdered Extract of Rhubarb, Extractum Rhei Alco-holicum; Fr. Extrait de Rhubarbe; Ger. Rhabarberextrakt.)

Fig. 100. - European rhubarb: transverse section.

Manufacture: Macerate, percolate 100 Gm. with 80 p. c. alcohol until exhausted, reclaim alcohol, continue distillation until residue syrupy consistence, transfer to a dish, rinse still with little warm menstruum, which add to dish and evaporate to dryness at 70° G. (150° F.), frequently stirring; add magnesium oxide 5 Gm., + dried starch enough for extract to weigh 50 Gm., pulverize, mix thoroughly, pass through fine sieve; 1 Gm. represents 2 Gm. of the drug. Should be kept in small, wide-mouthed, tightly-stoppered bottles. Dose, gr. 3-10 (.2-.6 Gm.).

2. Fluidextractum Rhei. Fluidextract of Rhubarb. (Syn., Fldext. Rhei, Fluid Extract of Rhubarb; Fr. Extrait fluide de Rhubarbe; Ger. Rhabarberfluidextrakt.)

Manufacture: Similar to Fluidextractum Sabal, page 95; menstruum: 80 p. c. alcohol. Dose, v-30 (.3-2 Ml. (Cc.)).

Prep.: 1. Syruyus Rhei. Syrup of Rhubarb. (Syn., Syr. Rhei; Fr. Sirop de Rhubarbe; Ger. Rhabarbersirup (saft).)

Manufacture: 10 p. c. Mix fluidextract of rhubarb 10 Ml. (Cc.), spirit of cinnamon .4 Ml. (Cc.), add potassium carbonate 1 Gm., previously dissolved in water 5 Ml. (Cc.), and gradually add this to syrup q. s. 100 Ml. (Cc.). Dose, 3 j-4 (4-15 Ml. (Cc.)).

3. Pilulae Rhei Compositae. Compound Pills of Rhubarb. (Syn., Pil. Rhei Co.; Fr. Pilules de Rhubarbe composees; Ger. Rhabarber und Aloepillen.)

Manufacture: Mix rhubarb 13 Gm., aloes 10 Gm., myrrh 6 Gm., oil of peppermint .5 Ml. (Cc.), water q. s. 100 pills. Dose, 1-5 pills.

4. Pubis Hhei Compositus. Compound Powder of Rhubarb. (Syn., Pulv. Rhei Co., Gregory's Powder, Powder Magnesia and Rhubarb, Pulvis (Infantum) Antacidus; Fr. Poudre de Rhubarbe composee; Ger. Pulvis Magnesiae cum Rheo, Kinderpulver.)

Manufacture: 25 p. c Triturate together rhubarb 25 Gm., Jamaica ginger 10 Gm., then add gradually magnesium oxide 65 Gm.; mix thoroughly, pass through No. 60 sieve. It is pinkish-white, mobile, darker on exposure to moisture; microscopically - fine particles of magnesium oxide, numerous elliptical starch grains (ginger), .005-.06

Mm. (1/3000-1/400') broad, and fragments of vegetable tissues; polygonal starch grains (rhubarb), .002-.02 Mm. (1/12500-1/1250') broad; mounts in hydrated chloral T. S. - strongly effervesce, showing more clearly tracheae, parenchyma, starch grains or rosette aggregates of calcium oxalate; with solutions of alkalies - many fragments deep red. Dose, 3ss-l (2-4 Gm.).

5. Tinctura Rhei. Tincture of Rhubarb. (Syn., Tr. Rhei; Fr. Teinture de Rhubarbe; Ger. Rhabarbertinktur.)

Manufacture: 20 p. c Similar to Tinctura Veratri Viridis, page 101; 1st menstruum: glycerin 10 Ml. (Cc.), alcohol 50 Ml. (Cc.) water 40 Ml. (Cc.), finishing with diluted alcohol q. s. 100 Ml. (Cc.). Dose, 3ss-4 (2-15 Ml. (Cc.)).

6. Tinctura Rhei Aromatica. Aromatic Tincture of Rhubarb. (Syn., Tr. Rhei Arom.; Fr. Teinture de Rhubarbe aromatique; Ger. Aromatische Rhabarbertinktur.)

Manufacture: 20 p. c Similar to Tinctura Veratri Viridis, page 101 - using rhubarb 20 Gm., Saigon cinnamon 4 Gm., clove 4 Gm., myris-tica 2 Gm.; 1st menstruum: glycerin 10 Ml. (Cc), alcohol 50 Ml. (Cc.), water 40 Ml. (Cc.), finishing with diluted alcohol q. s. 100 Ml. (Cc.). Dose, 3ss-4 (2-15 Ml. (Cc.)).

Prep.: 1. Syrupus Rhei Aromaticus. Aromatic Syrup of Rhubarb.

(Syn., Syr. Rhei Arom., Spiced Syrup of Rhubarb; Fr. Sirop de

Rhubarbe aromatique; Ger. Gewurtzer Rhabarbersirup (saft).)

Manufacture: 3 p. c Dissolve potassium carbonate .1 Gm. in aromatic tincture of rhubarb 15 Ml. (Cc.), add this to syrup q. s. 100

Ml. (Cc.). Mix thoroughly. Dose, for a child with diarrhoea, 3j_2

(4-8 Ml. (Cc.)).

Unoff. Preps.: Aromatic Fluidextract, dose, xv-60 (1-4 Ml. (Cc.)).

Fluidglycerate, 100 p. c., glycerin 50, water q. s. Infusum Rhei (Br.),

5 p. c, dose, 3iv-8 (15-30 Ml. (Cc.)). Liquor Rhei Concentratus, 50 p. c, dose, 3ss-l (2-4 Ml. (Cc.)). Mistura Rhei Alkalini, 1.6 p. c.

Mistura Rhei Composita, 1.5 p. c. (fluidext.) + sodium bicarbonate 3.5, fluidext. of ipecac 3, glycerin 35, spirit of peppermint 3.5, water q. s. 100, dose, 3j-15 (4-60 Ml. (Cc.)). Pills, 3 gr., dose, 1-5. Pulvis Rhei et Magnesiae Anisatus, 35 p. c, heavy magnesium oxide 65, anethol 8, alcohol 10. Aqueous Tincture, Sweet Tincture, each 10 p. c, dose 3ij-4 (8-15 Ml. (Cc.)). Tinctura Rhei Composita (Br.), 10 p. c., + cardamom seeds 1.25, coriander fruit 1.25, glycerin 10, alcohol 45 p. c, q. s. 100, dose, 3ss-l (2-4 Ml. (Cc.)). Tinctura Rhei et Gentiancp, 7 p. c, + gentian 1.75. Vinum Rhei Compositum, 8 p. c. +. Dose, 3 j-4 (4-15 Ml. (Cc.)). Torrefied Rhubarb. - By roasting, the cathartic principle is volatilized and the full astringency left behind; long boiling will effect the same result.

Properties. - Aperient, purgative, astringent, stomachic, tonic. It increases saliva, gastric juice, bile, peristalsis, vascularity, and absorption. The cathartic effect comes first (4-8 hours), due to resins (mainly phaeoretin), emodin, etc.; then follows astringency from rheo-tannic acid; both actions being chiefly on the duodenum. The milk, urine, and sweat become colored, the first also acquiring bitterness and purgative properties. Purgation may result from its application to ulcers, abraded skin, or in poultices to abdomen.

Uses. - Diarrhoea, hemorrhoids, cholera infantum, chronic dysentery, dyspepsia, thread worms. With calomel good in bilious fevers; with magnesium oxide for stomach and bowel disorders. By association with other cathartics both rendered more efficient; sometimes used with opium.

Allied Plants: