220 PRACTICAL’ FORESTRY 
The Central American rubber is the species which 
will be most cultivated in the future, because it will 
grow on the uplands on well-drained soil. 
Milk is manufactured in the tropics from the albu- 
men of the coconut. The white albumen is ground 
extremely fine, and mixed with sufficient water to give 
it the consistency of cream. It is then used on fruit. 
A common tree in the Sandwich Islands is the 
candle-nut, from which ten thousand gallons of oil 
are annually produced. This is a good drying oil for 
paints. 
There are hundreds of tropical trees which pro- 
duce oils, tanning materials, and medicines of many 
kinds. The most important of all medicinal trees is 
the cinchona. This is the tree which yields Peruvian 
bark, from which quinin and other valuable alka- 
loids are extracted. It was named for the Countess 
of Chinchon, vice-queen of Peru, who was cured of 
the fever by the use of its bark. It is a native of the 
valleys of Peru, but is now cultivated throughout the 
tropics. The exploration and settlement of many 
fertile tropical districts would have been impossible 
without it. 
A very valuable genus of trees for the tropics is 
the Eucalyptus. There are many species adapted 
to many soils. They are natives of Australasia, but 
are now common throughout the warm regions of the 
