CRUDE DRUGS. 645 



rice starch, is more frequently mixed with inferior gums, espe- 

 cially the Mesquite gum. The tears of Mesquite gum are nearly 

 smooth, light yellowish-brown to dark-brown, more or less opaque, 

 but translucent and glassy when fractured. The powder is of a 

 whitish or grayish-white color. The gum is further distinguished 

 by not giving precipitates with lead sub-acetate, ferric chloride 

 and sodium borate. A'lesquite forms an adhesive mucilage and 

 can be used as an emulsifying agent. 



MASTICHE. MASTIC The dried, resinous exudation 

 from Pistacia Lentiscus (Fam. Anacardiacese), a large shrub 

 (p. 321) indigenous to the Mediterranean region. The resin 

 exudes through incisions made in the bark, and when dry is col- 

 lected. The chief source of supply is the island of Scio. 



De.scription. Somewhat globular or ovoid tears 3 to 7 mm. 

 long, pale yellow or greenish-yellow, translucent, having a glass- 

 like luster, comparatively free from a whitish dust ; brittle ; frac- 

 ture conchoidal, becoming plastic when chewed ; odor slight, bal- 

 samic ; taste mild, terebinthinate. 



Mastic is completely soluble in ether, acetone and volatile 

 oils. It is almost completely soluble in alcohol, the solution giv- 

 ing an acid reaction with litmus paper. 



Constituents. About 90 per cent, of a resin, consisting of 

 a-resin (mastichic acid), which is soluble in alcohol, and ^-resin 

 (masticin), which is insoluble in alcohol; a volatile oil, i to 2.5 

 per cent., with the balsamic odor of the drug and consisting chiefly 

 of d-pinene. A small quantity of a bitter principle is also present, 

 which is soluble in hot water and is precipitated by tannin. 



Sandarac (p. 81) is a resin which somewhat resembles mas- 

 tic. It occurs in pale yellow, cylindrical tears which are brittle 

 and not plastic on being chewed. It is soluble in alcohol and 

 ether, and only partially soluble in chloroform, oil of turpentine 

 and carbon disulphide. Sandarac consists chiefly of resin which 

 is composed of sandaracinic acid, sandaracinolic acid, sandaraco- 

 pimaric acid, small quantities of two other resin acids, and 

 sandaracoresene. It also contains about i per cent, of volatile 

 oil which is composed principally of pinene. 



Allied Plants. Various other species of Pistacia found in 

 India and Northern Af'-i-:a ^ield resins resembling mastic. Amer- 

 ican mastic is obtiincd from the Peruvian Peppertree {Schiniis 



