187 CONVOLVULUS SCAMMONIA 



colour, and usually of a more or less porous, and somewhat 

 bubbly appearance; when rubbed with the moistened finger it 

 readily forms a whitish emulsion, by which it is distinguished 

 from scammony resin; and when touched with hydrochloric acid 

 it does^ not effervesce, indicating the absence of chalk. Thin 

 fragments when viewed by transmitted light are translucent, and 

 of a greyish- or yellowish-brown colour. It has a peculiar odour, 

 resembling that of old cheese ; and when chewed it has very little 

 taste at first, but it causes afterwards a slight prickly sensation in 

 the back of the throat. Ether removes from 80 to 90 per cent, 

 of resin, and what remains is chiefly soluble gum, with a little 

 moisture. 



Medical Properties and Uses. The effects of both ordinary 

 scammony and resin of scammony are those of a certain and 

 powerful drastic cathartic, closely resembling jalap, but somewhat 

 more irritant and active. Scammony usually causes much watery 

 discharge, and frequently griping ; it is generally given in 

 conjunction with other purgatives. On account of its irritant 

 qualities it is contra-indicated in inflammatory conditions of the 

 alimentary canal : but it is particularly well adapted for cases 

 of constipation depending upon torpidity of the bowels. It is also 

 well adapted for children on account of the smallness of the dose 

 required, its little taste, and the safety and certainty of its 

 action ; hence in combination with calomel it is a common 

 vermifuge for children. It is also employed as a derivative 

 purgative in cerebral affections and dropsies ; and in other cases 

 where an active cathartic is required, when its use is not contra- 

 indicated by its irritant properties. As a purgative the resin is 

 commonly given in somewhat smaller doses than the ordinary 

 scammony of commerce, but when the latter is pure there is 

 scarcely any difference in their effect. 



Steph. & Church., Med. Bot., by Burnett, vol. i, pi. 60; Per. 

 Mat. Med., vol. ii, pt. 1, p. 600 ; Per. Mat. Med., by B. & R , 

 p. 626; Pharmacographia, p. 394; U. S. Disp., by W. & B., 

 pp. 785 and 1388; Buchner's Neues Repertorium, 1864 (13, 

 No. 10, p. 448); Bucbner, in Pharm. Journ., vol. xiv, 1st 

 eer., p. 38; Pharm. Journ., vol. xvii, 1st ser., pp. 37, 447, 451, 



