ON THE COMMERCIAL KINDS OF INDIA-RUBBER. 5 
After Condamine left South America, an engineer, named Fresnau 
(who had lived in that country for many years), having seen many ar- 
ticles made of india-rubber, endeavoured to find out its source. After 
many inquiries, he at last obtained from some fugitive Indians models 
in clay of the fruit and leaves. These he distributed about the coun- 
try, in the hopes of discovering the hitherto-unknown trees. His in- 
genious plan met with success, and he had the satisfaction of making 
boots and other articles out of the substance. The French Aimiey 
published an account of his discovery in 1751. 
Aublet seems to have been the next who contributed some informa- 
tion on the subject. In his ‘ Flora of Guiana,’ published in 1775, he 
says that the fruit of Hevea Guayanensis is much sought after by the 
natives for food, and that caoutchouc is collected in the following 
manner :— 
“ The natives begin by making at the base of the trunks a deep gash into 
the wood. They then make another incision from the upper part of the trunk, 
vertically downwards to the former one, and, at various distances, a number 
of oblique incisions running into the first. These incisions form channels for 
the oozing sap, and convey it into a vessel placed for this purpose at the foot 
of the tree. In this the sap collects, loses its moisture, and becomes a soft elastic 
mass, which, when quite fresh, is readily made to take the shape of any in- 
struments or vessels upon which it is applied, layer after layer. These are 
then dried by exposure to the fire. The moulds are sometimes made of un- 
baked clay, ms new ene removed by poe in water to soften them, so 
that the cao Sometimes they are made of baked clay, 
and removed i being broken to ieee ‘the elasticity of the caoutchouc 
enabling it to bear the violence necessary without injury to its structure." 
For a considerable time this kind of india-rubber remained a scien- 
tifie curiosity, its only applieation being for rubbing out dirt and 
pencil-marks, thus giving rise to its name. Dr. Priestly was the first 
who warmly recommended it to artists for this purpose. Mr, Naire, 
an instrument-maker, advertised, in 1771, india-rubber for “ drawers 
in pencil, in cubical pieces of half an inch, for three shillings each.” 
Edwards, in an account of a voyage up the Amazon, says about i a 
certain island and the iidis-rabbet trees (Hevea sp.) there met with :— 
“This island was covered with a fine forest, in which were abundance of 
Seringa trees all scarred with wounds. We made some incisions with our 
tresados, and the milk oozed out, and dripped in little streams. Its taste was 
agreeable, much like sweetened cream, which it resembled in colour. The 
trees were often of a great height, and from 2 to 3 fect in diameter, the iari 
