TROPICAL AGRICULTURE 



among Americans. The teeth are stained black as a result 

 of constantly chewing the Betel nut. It is considered to be a 

 preventive of dysentery. Areca nut is also used as a vermi- 

 fuge, especially in veterinary medicine, as a dentrifrice, and 

 also extensively in tanning. Ceylon exports about 8,000 tons 

 annually. 



QUASSIA 



The drug and insecticide material known as quassia has been 

 derived from two species of trees, one known as Quassia 

 amara in Surinam, and the other known as Picrasma excelsa of 

 Jamaica. The official drug quassia, used in Europe, is derived 

 from the first species, while in the United States the supply 

 comes from the second species. Surinam quassia is a shrub 

 5 to 15 feet high. The wood of the root and trunk is used 

 as the source of an extract which is employed as a bitter tonic 

 for medicinal purposes. This tonic is considered of unusual 

 value on account of the fact that it exercises few of the un- 

 favorable effects which are characteristic of tonics. The flow- 

 ers of the Surinam quassia are of a brilliant red color. 



The Jamaica quassia, on the other hand, is a handsome tree 

 attaining a height of 100 feet or more and a diameter of 3 feet. 

 This tree bears greenish flowers. The extract obtained from 

 the wood of this tree has been used for various purposes. It 

 is sometimes substituted for hops for the purpose of making 

 beer bitter. The wood is quite commonly used for cabinet 

 purposes, being of peculiar value on account of its immunity 

 to insect attacks. 



Quassia chips have been extensively used as a source of a 

 bitter insecticide, especially employed in the control of aphis 

 or plant lice. This material has been used perhaps most widely 

 in controlling the hop aphis in the Western States. For this 

 purpose, quassia has proved to be exceedingly effective and 

 cheap. The insecticide quassia is commonly prepared by boil- 

 ing one pound of quassia chips in one or two gallons of water, 



