CAOUTCHOUC AND GUTTA-PERCHA. 215 
in Borneo, Sumatra, and all the numerous islands of the straits of Singapore 
and the Indian Archipelago—the destruction of the stems, (270,000 in all,) caused 
by the rapidly increasing exportation—22,225 pounds in 1844, but already 25,533 
ewt. in the following three years—gave rise to serious apprehensions. And in 
fact, the exportation itself seemed to decrease soon after, for, after reaching 
11,114 ewt. in 1846, it amounted only to 8,091? cwt. in the following year and 
a half. It appears, however, to have since somewhat increased. 
Be this as it may, warnings were sent over from England to treat the trees 
more savingly, and to make incisions in, instead of felling, them. Frequent 
complaints were heard that in India people believed the primeval forests to be 
inexhaustible. That they are not so, and what pernicious consequences follow 
their devastation is proved best by the example of the West India islands. 
At the time of their discovery, these were all covered with the finest forests ; 
now fine forests are only to be found in the larger islands, which owe to them 
their abundance of water and fertility. The smaller islands, however, the forests 
of which have been recklessly destroyed, suffer from drought, and in part possess 
neither springs nor brooks. There is scarcity of fuel all over the West India 
islands ; in Cuba the sugar pans are heated with orange-wood, the sugar-cane 
not being sufficient for the purpose. ‘Though this example speaks loud enough, 
people in the East Indies have no ear for the warning, and seem bent on repro- 
ducing there the deplorable condition of the West India islands. The earnest 
entreaties from England remain unheeded, and the well-known botanist See- 
mann informs us that he could discover no gutta-percha tree even around Singa- 
pore. At some places the tree is grown by European settlers in gardens. The 
coasts of the Indian Archipelago, too, are already greatly denuded, while trans- 
portation from the interior is connected with great difficulties. 
Gutta-percha is brought to market partly in a liquid state, partly in small 
slices, or kneaded into blocks and rolls, in the cuts of which the layers are dis- 
tinctly visible of which the whole mass is composed. In this ease it is solid 
and hard, but still easily receives impressions by the nail. The color is more or 
less reddish brown, owing to pieces of bark contained in the mass. This con- 
tains, besides other substances, parts of plants of various kinds, sawdust, 
earth, &c., admixed with dishonest intent, and sometimes amounting to a fourth 
of the whole, especially as the trade at the principal place of export is almost 
entirely in the hands of the crafty Chinese. 
Gutta-percha, in itself, possesses little, if any odor; but it often smells 
strongly, as of rotten cheese, or of something sour, on account of admixed 
substances in a state of fermentation. At ordinary temperature, 0° 25’, it is 
hard, leathery, solid, and strong, so that, for many purposes, it is preferred to 
wood or horn; it is tough, very stiff, and little elastic, so as not to resume its 
original shape after much bending. At no temperature does it possess the 
elastic ductility of caoutchouc. It offers a considerable resistance; its solidity 
has been tried by various experiments. According to MacCayan a piece one- 
eighth of an inch thick is torn only by a pressure of 50 pounds. Payen put 
gradually increasing weights upon a very thin gutta-percha band 74" long, 
1” 44’ broad, and not fully ;$4,/” thick, until it tore; this took place under 
a pressure of more than 44 pounds, the band, in the meanwhile, having ex- 
panded to 1’ 14”, that is to say, almost to double its length. Fermantel has 
found that every square line of the diameter of a gutta-percha band could bear, 
before tearing, a pressure of 25 pounds. The line of division marking where 
the elasticity begins to be tasked, would, according to these experiments, fall on 
five pounds for every square line, or 720 pounds for a square inch. Ata higher 
temperature, by which gutta-percha is softened, tearing ensues much sooner, 
and the latter, therefore, frequently proved a failure when services were de- 
manded of it which did not agree with its nature. 
The most remarkable peculiarity of this substance, which makes it appro- 
