common with the jebong cut panel. The rubber is gath- 
ered after a few days and the tree may be tapped again, 
although a tree is seldom tapped more than six times in 
one season. 
Well prepared chapa is a good rubber, because what- 
ever little dirt normally adheres to it can be easily re- 
moved before selling. There are several tricks employed 
by the natives to add weight to the rubber. The most 
common of these is to turn over the coagulated latex 
before making a new cut and then to allow the second 
flow to cover the dirty surface. When this chapa is re- 
moved it presents two smooth and clean surfaces. A wise 
buyer soon learns to be suspicious of rubber which is too 
smooth and clean on both surfaces, so the tappers occa- 
sionally leave the first chapa in the hole, kick in a small 
amount of dirt and allow the new latex to flow in and 
cover the dirt with rubber. This is more difficult to de- 
tect unless the piece of rubber is suspiciously large, since 
one surface issmooth and the other slightly rough. Care- 
ful buyers have all the large pieces cut up because this 
practice not only allows them to calculate the discount 
which must be made for the dirt, but enables them to 
dry the rubber faster, sell it at a better price as a grade 
with higher rubber content, and reduce the freight and 
taxes which are based on weight. 
Many property owners in the Serra do Machado are 
planting manisoba seeds with other crops. Snr. José 
Velosa of Sitio Valtiburi has planted 900 kilos, about 
810,000 seeds. He plants beans, corn, cotton, mandioca, 
castor beans and manisoba at the same time in his field, 
and the harvest is made in this order. At the end of two 
years only a few plants of castor bean and cotton remain 
and the mangabeira is ready to be tapped. 
Most of the rubber produced in Piaui, the state west 
of Ceara, is chapa. It is collected in a hole dug in the 
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