RHEUM. 317 



Composition. Hamamelis contains traces of tannic acid, 

 odorous matters, etc. Its active principle appears to be 

 unknown. 



Non-officinal Preparations. 



Hamamelin, a powdered Extractive; Dose, \ to 2 gr. 

 Tincture (1 to 10) ; Dose, 2 to 5 min. Fluid Extract (1 in 1) ; 

 Dose, 10 min. to 2 fl.dr. 



ACTION AND USES. 



Hamamelis is an astringent and haemostatic both locally 

 and remotely, useful in haemorrhages from the nose, lungs, 

 rectum, or uterus. 



POLYGONACE^E. 



Rhei Radix RHUBARB ROOT. The dried root 

 deprived of the bark, from one or more undetermined 

 species of Rheum. From China. Chinese Tartary T and 

 Thibet. Imported from Shanghai and Canton. 



Characters. Trapezoidal, roundish, cylindrical, or flattish 

 pieces, frequently bored * with one hole, yellow externally, 

 internally marbled with fine waving greyish and reddish lines, 

 finely gritty under the teeth ; taste bitter, faintly astringent 

 and aromatic ; odour peculiar. 



Composition. The active purgative principle of rheum is 

 probably identical with cathartic acid, the purgative constituent 

 of senna. "With this is combined rheo-tannic acid, possessing 

 astringent properties. The yellow colouring matter is chryso- 

 phanic acid in small quantity ; now made from araroba, and 

 used for other purposes. (See page 231.) Chrysophan, CigHjgOg, 

 is a yellow crystalline bitter glucoside. Emodin, phaoretin, and 

 oxalate of lime (35 per cent.) are less important constituents. 



Impurities. English rhubarb, known by taste, odour, and 

 excess of starch. Turmeric, reddened by boracic acid. 



Dose. As a stomachic, 1 to 6 gr. ; as a purgative, 10 to 

 20 gr. 



Preparations. 



1. Extractum Rhei. Spirituous. 100 in 39. Dose, 3 to 10 gr. 



2. Infusum Bhei. 1 in 40. Dose, 1 to 2 fl.oz. 



3. Filula Rhei Composita. Rhubarb, 3 oz. ; Socotrine Aloes, 



2 oz. ; Myrrh, l oz. ; Hard Soap, l oz. ; Oil of Pepper- 

 mint, 1 fl.dr. ; Treacle, 4 oz. Dose, 5 to 10 gr. 



4. Pulvis Bhei Compositus. " Gregory's Powder.'* Rhubarb, 



2; Light Magnesia, 6; Ginger, 1. Dose, % to 1 dr. 



