CRUDE DRUGS. 521 



amorphous, bitter glucoside, to the amount of o.ii to 1.74 per 

 cent. ; cinchotannic acid from 2 to 4 per cent., which decom- 

 poses into the nearly insoluble cinchona red, occurring in red 

 barks to the extent of 10 per cent. ; considerable starch ; calcium 

 oxalate in the form of cryptocrystalline crystals ; and ash about 3 

 per cent. The red color in cinchona bark is due to an oxydase 

 similar to that which causes the darkening of fruits when cut. 

 If the fresh bark is heated in boiling water for 30 minutes and 

 then dried it does not become red (see also Figs. 226, 233). 



Allied Plants. Loxa or Huanco (Cinchona pallida) bark 

 is obtained from Cinchona officinalis, a shrub indigenous to Ecua- 

 dor, which was the species first discovered. The plant is culti- 

 vated in nearly all the large cinchona plantations and yields a bark 

 (Fig. 226) that contains i to 4 per cent, of total alkaloids, from 

 one-half to two-thirds of which is quinine. 



CuPREA BARK is obtained from Rcmijia Purdicana and R. 

 pediincnlata, of Central and Southern Colombia. It has a copper- 

 red color, is hard, compact and heavy, contains numerous trans- 

 versely elongated stone cells and 2 to 6 per cent, of alkaloids, of 

 which one-third may be quinine. Cinchonidine has never been 

 isolated from this bark. Cuprea bark also contains caffeate of 

 quinine and caffeic acid, of which there is about 0.5 per cent., 

 and which closely resembles the same acid obtained from caffeo- 

 tannic acid in coffee. 



FRANGULA. ALDER BUCKTHORN BARK. The 

 dried bark of the stem and branches of Rhamnus Frangnla (Fam. 

 Rhamnacese), a shrub indigenous to Europe, Northern Africa and 

 Central Asia ; and naturalized in Northern New Jersey and Long 

 Island. The bark is collected in spring and kept at least one year 

 before being used, so as to render inert the irritating and nauseat- 

 ing principles which are destroyed by a ferment during the curing 

 of the drug. The same results are said to be obtained by heating 

 the bark at 37.7 C. for 48 hours (p. 326). 



Description. In single or double quills and transversely 

 curved pieces, 2 to 20 cm. long, i to 3 cm. in diameter, bark 0.3 

 to I mm. thick ; outer surface dark brown or purplish-black, 

 longitudinally wrinkled, with numerous lenticels i to 3 mm. long, 

 and with grayish patches of foliaceous lichens and groups of 



