4O2 RUBIACE^ 



bast fibers are more numerous and stouter. The bark is richer in 

 coloring matter. In cuprea bark the cork cells are thicker and the 

 cortical parenchyma cells smaller, stone cells present, milk-ducts 

 absent, few bast fibers, but the woody portion contains indurated 

 cells, which simulate them. The ligneous cells are very numerous and 

 extend even down into the medulla. They are smaller than the bast 

 fibers of true cinchona barks, but much more numerous. 



These barks are thoroughly saturated with pigments, principally 

 cinchona red, the phlobaphen of all cinchona barks. Before micro- 

 scopical examination these pigments must be removed by a weak 

 alcoholic solution of ammonia. This requires considerable practice 

 (Dohme). Compared with other barks, the fibers of the liber of 

 cinchona are shorter and more loosely arranged, being for the most 

 part separated into simple fibers imbedded in the bast parenchyma, 

 or united into very short bundles. 



Grahe's test for the distinction of cinchona bark is as follows: On 

 heating about o.i Gm. (ij^ gr.) of the powdered bark in a dry test- 

 tube a tarry distillate of a red color is obtained. 



Powder. Microscopical elements of: See Part iv, Chap. 1, B. 



OFFICIAL PREPARATIONS. 



Fl. Ext. Cinchonae, Dose: 15 nj. (i mil). 



Tr. Cinchonae, I fl. dr. (4 mils). 



532 a. CINCHONA RUBRA. The dried bark of Cinchona Succirubra 

 Pavon or its hybrids, yielding not less than 6 per cent, of the total 

 alkaloids of Cinchona. "In quills or incurved pieces, varying in 

 length, and from 2 to 4 or 5 mm. (^2 to % or li m -) thick; the outer 

 surface covered with a grayish-brown cork, more or less rough from 

 warts and longitudinal, warty ridges, and from few, mostly short and 

 not frequently intersected transverse fissures, having their sides slop- 

 ing; inner surface more or less deep reddish-brown and distinctly 

 striate; fracture short, fibrous in the inner layer; outer layer, granular. 

 For years practically all of the red cinchona bark, so called, was only 

 a hybrid, but recently, and especially for a year past, fine quill bark 

 of pure succirubra has frequently been received. 



Powder. Microscopical elements of: See Part iv, Chap. I, B. 



CONSTITUENTS. Upon quinine, CwHu'NzOzsH.zO, the bark almost ex- 

 clusively depends for its value. This alkaloid is colorless, amorphous, 

 or in acicular crystals; inodorous, very bitter; soluble in 1670 parts 

 water, 6 parts alcohol, 26 parts ether. Aqueous solutions of the salts 

 have a blue fluorescence, and when treated with chlorine water and 

 ammonia a beautiful green color is produced "Thalleoquin test." 

 The solutions deviate the plane of polarization to the left. The tar- 



