ACTIONS AND USES 459 



With starch, cellulose, uncrystallisable sugar, and gum, 

 jalap contains 9 to 11 per cent, of the active resin, con- 

 sisting chiefly of the glucoside eonvolvulin, which differs 

 from the jalapin of scammony in being insoluble in ether. 

 Jalap resin occurs in dark-brown fragments, readily re- 

 duced to powder, with a sweetish odour, and acrid taste. 

 Soluble in rectified spirit, but not in water or in oil of 

 turpentine. 



ACTIONS AND USES. Jalap is a hydragogue cathartic, 

 and a vermifuge. The ordinary jalap closely resembles 

 the larger-rooted male jalap, or orizaba root, the smaller 

 paler tubercules of the tampico root, the dried root of 

 Convolvulus scammonia, and the roots of Bryonia alba and 

 B. dioica, as well as the Kaladana seeds used roasted 

 as a purgative by the nations of Hindustan. It is more 

 active than senna, the leaves of Cassia acutifolia, and 

 the other anthracene purgatives, but less powerful and irri- 

 tant than the drastics, gamboge, podophyllum, elaterium, 

 and colocynth. 



Jalap has very gentle cathartic action on either horses or 

 cattle. Two or three ounces given to the horse have slight 

 effect on the bowels, but increase the activity of the kidneys 

 (Moiroud). White reports administering half a pound to 

 horses without causing purgation. Dun repeatedly gave 

 cows four ounces without perceptible effect. Probably the 

 B.P. jalap resin would be more energetic. For dogs, cats, 

 and pigs it is, however, a good purgative, although full doses 

 occasionally produce nausea and sometimes vomiting. It is 

 prescribed for most purgative purposes, acts tolerably 

 speedily and certainly, produces full watery discharges, 

 and is specially effective when given with a grain or 

 two of calomel. As with several other purgatives the 

 presence of bile in the intestine is necessary for its 

 action. 



DOSES, etc., of Jalap powder. Dogs take 3i. to 3ij. ; 

 cats, grs. iv. to grs. xx. ; pigs, ^i. to ^iv. It is best given 

 in combination with calomel. Dogs, if fasted for six hours, 

 are effectively purged in three or four hours by 3 SS - to 3*- 

 of jalap, with two or three grains of calomel, made into 

 bolus with any convenient excipient. 



