1 Mar., 1899.] QUEENSDAND AGRICULTURAL JOURNAL. 197 
Tropical Industries. 
THE EXHAUSTION OF GUTTAPEROGHA. 
Gurravercita, caoutchoue, and rubber are usually supposed to be synonymous 
terms, but this isnot so. Guttapercha is derived from a tree whose bofanical 
name is Lsonandra Gutta, and also from another tree, Dichopsis Gutta. : These 
trees grow wild in the Malay Peninsula. ‘To obtain the sap, the trees are first 
felled with axes, because the usual method of collecting rubber by simple incisions 
in the bark is insuflicient in the case of the guttapercha-tree. After felling, 
incisions are made in the bark at distances of from 6 to 18 inches apart, to 
cause the flow of the milk or sap, which, as it flows from the incisions, is caught 
in palm leaves, cocoa-nut shells, and other primitive vessels, but more or less 
escapes to the ground, and this is gathered up along with sand and other 
particles of foreign matter. In some instances, when small quantities are 
collected, the milk is inspissated or concreted by being rubbed between the 
hands. As # generai rule, however, it is boiled in iron pans with the addition 
of various adulterants. Among their adulterants, other than the juice 
of allied plants, is cocoanut oil to improve the appearance, and also lime 
juice, which has the property of coagulating the guttapercha immediately on 
ebullition. In Borneo, some 20 per cent. of scraped bark is added, and it is 
said that the Chinese, who purchase the article from the gatherers, prefer it 
when containing this bark, on account of the red colour itimparts. The purely 
crude guttapercha is the article in the fluid state as it flows from the tree. 
It being, however, impracticable to preserve and market it in this condition, 
it is prepared and manipulated in the manner above stated for the purposes of 
transportation and market. 
Caoutchouc is the product of many trees and vines growing in different 
parts of the tropical world, all of the Mcus family. The richest caoutchouc or 
rubber-producing zone is on the banks of the southern tributaries of the 
Amazon, in Brazil, on the island in the main stream, and near Para. This area 
contains at least 1,000,000 square miles, on which grows an inexhaustible supply 
of the Hevea Braziliensis, a rubber-producing tree which grows much like an 
English ash, and attains a height of 60 feet. 1t thrivesin low, swampy country, 
requires the shade of other trees and still air, and takes fifteen years to mature. 
It is being continually reproduced by nature, and an exhausted area, when lett 
alone for some time, will recover. A hundred Para rubber-trees will yield as 
much as 1 ton of rubber per annum. The trees are not eut down as in the case 
of the Isonandra Gutta, but are tapped as they stand, and hence are “not 
destroyed. 
The Castilloa elastica, whence large supplies are obtained, ranges from 
Mexico, through Central America into northern South America. Unlike the 
Hevea of the Amazon, it does well in dry, healthy ground, where a man from 
the temperate regions of the earth can expect to live and see his trees develop. 
It reproduces itself in suitable localities, but it is essentially a tree of the 
shade, like our huge scrub Moreton Bay figs (also rubber-producers). Destroy 
the scrub, and the tree, being exposed to the fierce rays of the sun, immedi- 
ately begins to thicken its naturally tender, thin bark at the expense of the 
flow of sap. Hence, in many cases, where thousands have been expended on 
establishing plantations of the Oastilloa trees, the result has been total loss. 
On the other hand, a careful selection of a run of forest property, where 
rubber-trees reproduce themselves naturally, must yield returns that will exceed 
the most sanguine expectations. 
