50 MATERIA MEDICA. 



transverse fissures ; epidermis often wanting ; texture fibrous ; frac- 

 ture splintery, exhibiting minute spiculte ; colour of bark, yellow- 

 orange ; taste, bitter and nauseous ; odour, slight ; relative value 

 superior to the others, as it abounds most in quinia. 



Red Bark {cinchona rubra). — Supposed to be derived from the 

 larger branches and trunk of the same tree which yields the pale 

 bark ; size of quills, half an inch to two inches in diameter, and two 

 to twelve inches long ; flat pieces are large and thick ; external co- 

 lour reddish-brown, with a very rough epidermis, which occasionally 

 exhibits warts upon it; colour of powder reddish; taste, very bitter. 



The 'p<^/'^ bark contains most cinchonia, the yellow most quinia, 

 and the red about an equal portion of both alkalies. 



The varieties of bark called Carthagena barks are much inferior 

 to those just described. They are all shipped from the northern 

 or Atlantic ports of South America. 



Cinchona yields its virtues to water and alcohol. Its active prin- 

 ciples are two alkalies named quinia and cinchonia^ which exist 

 combined with kinic acid, 



Quinia is prepared by macerating Calisaya bark in water, acidu- 

 lated with sulphuric acid ; this acid forms the soluble supersulphate 

 of quinia ; filter, and add lime, which throws down the sulphate of 

 lime, along with the quinia ; next add boiling alcohol, which takes 

 up the quinia, which may then be decolorized by animal charcoal, 

 and separated by evaporation. It occurs in a white flocculent powder ; 

 nearly insoluble in water ; very soluble in boiling alcohol, ether, and 

 volatile oils ; unites with acids to form salts, of which the most im- 

 portant is the officinal sulphate. Cinchonia is a white crystalline 

 substance, with general properties resembling those of quinia. 



Incompatibles. — The alkalies, alkaline earths, and tannic acid. 



Physiological effects. — A tonic in small doses, and also anti- 

 periodic ; the latter is peculiar, and is not dependent upon its tonic 

 properties. In full doses, apt to occasion oppression of stomach, 

 nausea, and purging ; also acts upon the cerebro-spinal system, as 

 evinced by the tension of the head, ringing of the ears, and occa- 

 sional deafness. 



Uses. — As a mere tonic, it is inferior to the simple bitters in dyspepsia, 

 but applicable in exhausting stages of disease, particularly in suppu- 

 rations. Its most important use is in intermittent diseases, especially 

 intermittent and remittent fever; believed to do good in these affec- 

 tions through the agency of the nervous system. 



Cinchona is given in powder, infusion, decoction, tincture, and 

 extract. Most powerful in substance, but apt to disagree with the 

 stomach, and offensive on account of its bulk ; dose 5j, repeated so 

 as to give 3,j to 3ij in the intermission ; its efficacy is increased by 

 combining it with serpentaria. Powdered bark sometimes used ex- 

 ternally, in the form of quilted jackets — applied to children. Dose 



