8 
REPOET ON THE CAOUTCHOUC OP COMMERCE. 
a distance of more than 1,700 miles. This central line which 
Mr. Wallace draws passes through the centre of the chief district 
for the Heveai. If a line be drawn from about Parahiba to about 
the point of junction of the River Araias with the Madeira, then 
continued in a north-west direction to the source of the Meta 
(tributary of the Japura), then diverging it in a north-east direction 
to the junction of the Urichunge with the Orinoco, continuing this 
in an easterly direction, following the coast when intersected by the 
line till the Oyopok is reached, and continuing the line down it, 
and finally finishing the line at Santarem, it will enclose the whole 
of the Hevea region. 
Collection and Preparation op Para Caoutchouc. 
The collection commences as soon as the waters have sub- 
sided, namely, in August, and continues till January or February. 
In the wet season the milk is too aqueous to allow of profitable 
collection. The milk is at first of the consistence and colour of 
cream. This soon changes its consistence by the coalescence of the 
particles of Caoutchouc, which are suspended in a thin whey-like 
liquid. Each morning the collectors visit the trees which have 
been incised the preceding evening and collect the milk. To obtain 
the milk from the tree, with a machete or knife a deep horizontal 
cut is made a few inches above the base of the tree ; from this cut a 
vertical one is made extending high up the trunk. On either side 
of this vertical cut others are made at short distances in an oblique 
direction and meeting it (Pig. 6). The cuts form channels down 
which the milk runs, and which is received at the base in clay, shells, 
or other vessels. Sometimes the yield of the tree is increased by 
binding the trunk with cords or bands formed of the stems of twining 
plants (lianas or sip6s), resulting often in the death of the tree.* 
When a sufficiency of milk has been collected, means are adopted to 
bring about the coalescence of the Caoutchouc. The method more ge- 
nerally adopted is by pouring the milk over clay or wooden moulds, 
and drying each successive pouring by means of a gentle heat. 
Into a brazier or pan, or pots with narrow necks, heated with wood 
from beneath, the fruits of various palms are placed ; those of the 
Urucuri ( Attalea excelsa , Mart.) are generally used, but when these 
are not procurable, those of Maximilians regia or Astrocaryum 
* From the frontispiece given in Mr. Wickham’s book (v. ante) it appears that the 
barbarous method of denuding the tree for a considerable space of its bark is also 
resorted to. 
