THE HEVEA RUBBER TREE IN THE AMAZON VALLEY 
15 
no market at all were it not that a washing plant now exists in that 
city which washes, sheets, and dries this rubber. Considering the 
raw material it uses, this plant turns out a product of surprisingly 
good quality. 
The machadinho employed in tapping usually has a cutting edge 
about 2.5 centimeters long, but the writer observed on the Rio Ouro 
Preto in Matto Grosso and elsewhere the use of machadinhos with an 
edge 7.5 centimeters long. In former times the machadinho was 
supposed to be made of iron, never of steel. Some thought this was 
because steel in some mysterious way injured the tree; others said 
that the iron ax could not be kept sharp and being dull would not 
penetrate to the cambium and therefore would not damage the tree. 
Woodroffe and Smith '{48) as late as 1915 continue to perpetuate this 
supposition. Judging from the trees tapped in the iron age of the 
machadinho, one is compelled to believe that the ax rarely failed to 
reach the cambium. 
Fig. 6. — Knapsack rubber at Tres Casas, on the Madeira River. This rubber is coagulated by 
smoking latex over a rectangular paddle. Each knapsack represents the collection of one man 
for one day 
When plantation rubber first came into tapping in the East a great 
controversy, now merely of historical interest, arose as to the best 
method of tapping. Two rival schools sprang up. One insisted 
that the trees must be incised, as with a machadinho or other sharp 
instrument. The other group was for excision, that is, paring away 
the outer bark with a farrier's knife or a gouge, so as to open the latex 
vessels. The incisionists predicted the destruction of all the planta- 
tions by the arboricidal method of excision, which was not the tradi- 
tional treatment to which the tree had been accustomed in its native 
jungles. They also expatiated on the harmlessness of the use of 
the machadinho and the great care with which this instrument was 
used. 
If there ever were seringueiros who were careful in using the 
machadinho the tribe has vanished from the soil — and the waters — of 
the Amazon area! It is hard to imagine what the incisionists thought 
the ever-present knots and swellings around the base of the tree might 
