234 



LEGUMINOS^E 



glabrous, midrib sometimes depressed, veins of first order more or 

 less prominent; under surface light grayish-green, midrib prominent, 

 minutely pubescent, especially near the veins; petiole about i mm. 

 long; texture coriaceous, fibrous; odor slight; taste somewhat bitter. 

 Powder: Light green; non-secreting hairs o.i to 0.2 mm. long, one- 

 celled, thick-walled, the wall of the upper part strongly cuticularized; 

 calcium oxalate crystals rosette- shaped or in monoclinic prisms. The 

 powder of Indian senna (C. angustifolia) is dark green and has rela- 

 tively few non-secreting hairs. (For fuller particulars of the micro- 

 scopical distinction of the two powders, see article 

 by the author, "Amer. Jour. Pharm.," June, 1897, 

 p. 298.) The India senna is by far a cleaner senna; 

 senna should be free from stalks and other inert 

 materials, and from Argel leaves (Solenostem'ma ar'- 

 gel, N. O. Asclepiadeae) , which are thick, even at 

 the base, and one-veined. 



Powder. Characteristic elements: See Part iv, Chap. I, B. 

 CONSTITUENTS. The purgative action of senna depends 

 upon a sulphuretted glucoside, cathartic acid, 

 insoluble in alcohol, soluble in water, but rend- 

 ered partially or wholly inert by prolonged evapora- 

 tion or boiling of its solution. Senna also contains 

 chrysophan, phaeoretin, sennacrol, and glucosennin, 

 CazHisOs; this latter is probably an emodin glucoside. The 

 emodin is said to be identical with that fpund in Barbadoes and 

 Cape Aloes. The principles giving the odor and taste to senna, also 

 its griping action, are extracted by alcohol, somewhat affecting 

 the cathartic action, however. Ash, not more than 12 per cent, 

 not less than 3 per cent.; insoluble in HC1. 



EMODIN TEST. This test is applied to the emodin-bearing drugs such 

 as Rhubarb, Aloes, Senna, etc. The tests as applied are practically 

 the same. For Senna it is as follows: Mix 0.5 Gm. of powdered 

 Senna with 10 mils of an alcoholic solution of potassium hydroxide 

 (i in 10), boil the mixture for about two minutes, dilute it with 10 

 mils of water and filter. Now acidify the filtrate with hydrochloric 

 acid, shake it with ether; remove the ethereal layer and shake it with 

 5 mils of ammonia water; the latter is colored yellowish-red. 



Preparation of Cathartic Acid. Rhubarb or senna may be treated separately 

 as follows: Moisten the drug with alcohol. Macerate 48 hours and percolate 

 with strong alcohol till exhausted, to remove chrysophanic acid, resin, etc. Ex- 

 haust the marc with 60 per cent, alcohol. Evaporate the percolate at 5OC. to 

 syrup, with constant stirring. Precipitate extract with 85 per cent, alcohol and 

 filter to remove gum. The filtrate, after evaporating to a syrupy consistence, is 

 added to a large excess of absolute alcohol. The brown precipitate thus produced 

 is spread on glass to dry. It is then in light, shining scales. 



FIG. 125. A, Alexan- 

 dria senna. B, India 

 senna. 



