86 MATERIA MEDICA. 



be adulterated. Virtues imparted partly to water, and partly to 

 alcohol. Active ingredient is a resin ; it contains also much starch, 

 and some gum and sugar. 



Effects. — A powerful hydragogue cathartic; much used in dropsies 

 and chronic affections of the joints, particularly in combination with 

 cream of tartar. Dose, 15 to 30 grs.; dose of calomel and jalap, 10 

 grs. of each, — used in bilious complaints; dose of jalap and crem. 

 tartar, 10 to 20 grs. of the former, and 2 to 4 drachms of the latter. 



The M^sin of Jaiap is the alcoholic extract; dose, 8 to 10 grs. 

 Extract^ Jalap is used in doses of 10 to 20 grs.; the tincture is 

 also officinal. 



.."The May apple [Podoj^hyllum peltatum), an indigenous peren- 

 nial plant, possesses very similar medical properties to those of jalap. 

 The root, which is the part used, is very long and branching, of a 

 brownish colour externally. It may be employed in the same cases 

 as jalap. Dose, the same. 



COLOCYNTH. (COLOCYNTHIS, U. S.) 



Fruit of the Cucmnis colocyntkis, or Bitter cucumber, a vine re- 

 sembling the common cucumber, growing in the south of Europe, 



Fig. 22. 



Asia, and Africa. Fruit about the size and shape of an orange ; has 

 a yellow rind, and a white, light, and porous pulp, containing nu- 

 merous seeds. As found in the shops, it is usually divested of the 

 rind. Taste, extremely bitter ; virtues, to water and alcohol ; the 

 infusion gelatinizes on cooling in consequence of the pecti7i con- 

 tained ; active principle, colocynthin. 



Effects. — A powerful hydragogue, producing in over-doses inflam- 

 mation of the bowels. Not much used alone, — Dose, 5 to 10 grs. 

 The compound extract, {ext. colocijnthidis composituniy U. S.,) is an 



