CHAPTER XIV 



DRUGS 



No attempt is made in the present discussion to consider 

 other than a few of the important commercial drug plants 

 which grow primarily or exclusively in tropical countries. 

 There are thousands of plants which have been used for the 

 extraction of drugs. In fact, few plants have escaped the 

 suspicion of possessing a medicinal property of one sort or 

 another. In looking over the long list of drug plants one is 

 reminded of the fact that a large percentage of them grow in 

 northern climates. Some of the drug materials which it might 

 be expected would be discussed in this chapter are referred to 

 elsewhere. For example, castor oil and star anise oil are 

 treated under oils. 



CINCHONA 



Cinchona trees, from which are obtained the alkaloid quinin 

 and other related alkaloids, are native to South America, where 

 they grow in abundance from a latitude of 10° N. of the 

 Equator to about 20" S. The chief species which have been 

 used as a commercial source of quinin are Cinchona ledgeriana, 

 which yields the so-called yellow bark; C. succirubra, from 

 which red quinin or red bark is obtained; C. aiUcinalis, from 

 which brown bark or pale bark is obtained ; and C. calisaya, the 

 source of calisaya bark. Until about 1890 practically all the 

 cinchona bark of commerce was obtained from wild cinchona 

 trees. Since that date the trees have been cultivated quite 

 extensively, particularly in Java, Bengal, Ceylon, and Mada- 

 gascar. Cinchona occurs as a shrub or tree reaching a height 



214 



