2 BULLETIN 1422, IT. S. DEPARTMENT OF AGRICULTURE 
it is called "Hheve," or "Jeve," according to the Spaniards, but 
that the Mai'nas Indians to the east of the Andes call it " caoutchouc," 
while the Portuguese call it "Pao de Xiringa." In the same pub- 
lication La Condamine gives a description and a very poor picture 
of the rubber tree, which obviously belongs to the Hevea group. 
In 1770 Priestley discovered that india rubber would erase pencil 
marks, and small quantities were soon on the market, offered at a 
high price, for this purpose. This, however, was really India 
rubber, since it came from India and not from South America. 
Further uses for rubber were not rapidly discovered by civilized 
man, for it was not until 1823 that Charles Mcintosh found that rub- 
ber was soluble in benzine and could be used for making waterproof 
coats. Prior to this garments had been waterproofed by coating them 
with latex from the rubber tree, and explorers and early travelers in 
South America found garments and bags so treated very useful. 
But since the coating had to be put on with latex freshly drawn from 
the tree the process was of very limited application. 
The successful use of this substance by Mcintosh stimulated an 
interest in its application for other purposes. Boots and shoes were 
made of rubber, and at one time the city of Para, in Brazil, manu- 
factured them in considerable quantities. However, these articles, 
though waterproof, showed a tendency to freeze in cold weather and 
to become sticky or tacky in warm weather. 
The accidental discovery by Goodyear in 1839 that rubber could 
be vulcanized by mixing it with sulphur and heating it removed the 
bar to the successful application of this remarkable substance to a 
great variety of uses. The demand for rubber rapidly increased, 
and a great many different plants in various part of the world were 
exploited for their rubber content. Of all these, the Para rubber 
tree {Hevea brasiliensis) growing in the valley of the Amazon River 
was found to yield the greatest quantity as well as the highest quality 
of rubber. Richard Spruce (.40), the noted plant explorer and 
collector, records that in 1849 rubber was collected from this tree 
only in the vicinity of the city of Para, but that by 1854 the industry 
had become so important that in the State of Para alone it occupied 
the efforts of 25,000 persons, and the collectors had ascended far 
up the tributaries of the Amazon. 
In the process of collecting rubber many plants could be utilized 
only by destroying them completely, so that the visible supply of 
rubber steadily decreased while the consumption of this commodity 
was ever on the increase. This led to the consideration of the possi- 
bility of cultivating rubber-bearing plants, and various species 
were made the subject of experimental plantings. Most of these 
were found unsuitable for commercial cultivation, but a few gave 
promise of success. Hevea brasiliensis was introduced into India, 
Ceylon, the Straits Settlements, and the Dutch East Indies by 
Wickham (46), who took seeds from the Amazon region to Kew in 
1876. It soon became apparent that this was one of the most suit- 
able plants, if not the most suitable, for cultivation, though the Cen- 
tral American rubber tree (Castillo, elastica) was highly, though un- 
wisely, recommended for planting in such places as Trinidad. In 
certain dry areas the Ceara rubber tree (Manihot glaziovii) gave 
promise of profitable yields, at least while the price of rubber was 
high. 
