RADIX GENTIAN.B. GENTIAN. 11$ 



ters, deeply stained, are met with in the powder ; they 

 are said to be chrysophanic acid. The parenchyma is 

 abtmdant, very thin- walled, wide-meshed, and usually 

 crowded with starch. PecuHar strings of flattened 

 parenchymatic tissue are frequent. 



The vessel fragments are usually large and show the 

 conspicuous reticular markings; sometimes annular and 

 spiral vessels are observed. 



The fibres are few and present the characters of short 

 wood fibres, with usually less thickened walls. 



Chemistry. — The official rhubarb contains chrysophan, 

 emodin, and the three resinous bodies, aporetin, eryth- 

 roretin, and phaeoretin; also rheo tannic acid, cathar- 

 tinic acid, a bitter substance, a crystalline body allied to 

 cantharidin, 1.5 per cent, oxalic acid, traces of a volatile 

 oil, and 3.43 per cent. ash. 



RADIX GENTIANS. GENTIAN. 



The root of Gentiana lutea, L. (nat. ord. Gentianece), 

 U. S. P. The official gentian is a stately yellow-flowered 

 perennial herb, 2 to 4 feet high, growing in central and 

 southern Europe. The drug is also obtained from 

 several unofficial species, as G. purpurea, L., G. pan- 

 nonica, Scopoli, and G. punctata, Linn6. 



Description. — Gentian comes in pieces of about 10 

 cm. in length and from i to 1.5 cm. in thickness, being the 

 entire thickness of the smaller roots and longitudinal 

 slices of the larger. It is sometimes cut obliquely in 

 cross-sections. The heads of the official root are closely 

 annulated, the others scarcely so. In drying it contracts 

 one-third in thickness which causes its contorted ap- 

 pearance and deep longitudinal and spiral wrinkles. 

 The color is outwardly yellow or, from adherent earth, 

 brownish. 



The fracture is after a slight bending sharp, showing 

 a golden yellow interior. When cut, it shows a waxy 

 lustre. 



