CLASSIFICATION OF ANGIOSPERMS. 381 



annually in the latter country. The yield of one tree is between 

 I and 12 pounds. There are two methods of freeing the seeds 

 from the parchment-like endocarp: In the one case the fruits 

 are allowed to dry and are then broken ; in the other case, which 

 is known as the wet method, the sarcocarp is removed by means 

 of a machine, and the two seeds with the parchment-like endocarp 

 are allowed to dry in such a manner as to undergo a fermentation, 

 and after drying the endocarp is removed. Coffee seeds contain 

 from I to 2 per cent, of caffeine ; from 3 to 5 per cent, of tannin ; 

 about 15 per cent, of glucose and dextrin; 10 to 13 per cent, of a 

 fatty oil consisting chiefly of olein and palmitin ; 10 to 13 per 

 cent, of proteids ; and yield 4 to 7 per cent, of ash. The official 

 caffeine is derived in part from coffee seeds. 



In the Ro.\STiNG of coffee there is a change in the physical 

 character of the seeds, as well as a change in some of the constit- 

 uents. The AROMA is supposed to be due to an oil known as 

 coffeol, which is said to be a methyl ether of saligenin. 



Ourouparia Gambir is a liane climbing by means of hooks. 

 The leaves are ovate or oblong and coriaceous, with linear 

 recurved, interpetiolar stipules. The flowers are white, silky, and 

 arranged in single, axillary heads, like those in the button bush 

 (Cephalanfhus occidentalis). The fruit is a 2-valved, dehiscent 

 capsule with persistent calyx. The seeds are numerous and have 

 several filiform appendages. It yields Gambir (p. 666). 



A number of the Rubiacese contain valuable coloring prin- 

 ciples, as the madder plant (Rubia tinctoriim) , which is a peren- 

 nial herb occurring wild in Southern Europe and formerly culti- 

 vated in France and Germany on account of the coloring principle 

 in its roots. The root is known commercially as madder, and con- 

 tains when fresh a yellow coloring principle, which on the drying 

 of the root breaks up into several glucosides, one of which on 

 further decomposition yields alizarin, the principle to which the 

 red color of the dried root is due. At present alizarin is made 

 artificially from anthracene, a coal-tar derivative, and hence the 

 demand for madder has declined. 



Morinda citrifolia, a shrub widely distributed in tropical coun- 

 tries, contains a red coloring principle in the flowers and a yellow 

 coloring principle in the roots, the latter being known as morindin 



