CRUDE DRUGS. 451 



of bark tough, fibrous, of wood short and granular; internally 

 light brown, finely radiate, bark 0.5 to 2 mm. thick, and easily sep- 

 arable from the wood, cambium zone marked by a distinct brown 

 line, wood porous ; odor faint, aromatic ; taste sweetish, mucil- 

 aginous (Fig. 99, 5). 



Constituents. — Mucilage 25 to 35 per cent. ; asparagin 

 (amido-succinamide) i to 2 per cent., which occurs in hard crys- 

 tals with an acid reaction, insoluble in alcohol but soluble in 50 

 parts of cold water; starch about 35 per cent.; pectin about 10 

 per cent. ; sugar about 10 per cent. ; ash about 5 per cent. An 

 infusion of althaea is colored bright yellow with dilute solutions of 

 the alkalies. 



Allied Plants. — The roots of a number of other genera of 

 this family are used for similar purposes, as those of Kosteletzyka 

 pentacarpa of Southern Europe ; Hibiscus Bancroftianus of the 

 West Indies ; Malvaviscus pentacarpus of Mexico ; H. Rosa Sinen- 

 sis of tropical Asia and cultivated ; Althcea rosea of the Levant and 

 cultivated; and Sida ovalis of Peru. Mucilage is also found in 

 the flowers and leaves of one or more species of Malva, Sida, 

 Pavonia, Hibiscus, Pachira and Eriodendron. 



JALAPA. — ^JALAP. — The tuberous root or tubercle of Exo- 

 gonium Purga (Fam. Convolvulacese) , a perennial twining herb 

 (p. 365) native of the eastern slopes of the Mexican Andes, and 

 cultivated in Jamaica and India. The roots are collected in the 

 fall and dried by artificial means, the larger ones being first cut 

 into longitudinal pieces. Mexico furnishes the principal part of 

 the commercial supply, which is exported from Vera Cruz. 



Description. — Fusiform, irregularly ovoid or pyriform, upper 

 end more or less rounded, lower end obtuse or slightly acuminate ; 

 3 to 8 cm. long, i to 5 cm. in diameter; externally dark brown, 

 deeply and irregularly furrowed longitudinally, otherwise nearly 

 smooth or wrinkled, with numerous lenticels 2 to 4 mm. long and 

 few circular rootlet-scars ; fracture horny and resinous ; internally 

 dark brown and'marked by more or less distinct, secondary, concen- 

 tric camB!tim zones ; odor fruity ; taste starchy and slightly acrid. 



Tubercles which have a specific gravity less than 1.275 and are 

 white internally should be rejected. 



Inner Structure. — See Fig. 195. 



