DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.1311#0102
74 THE GREAT EXHIBITION
emulsions produced from seeds collects on the surface of the aqueous liquor, is, properly
speaking, a fatty body containing oxygen in its composition, as they all do; while the
kind of cream which swims upon the milky juice of the plants when left to itself, is one
of the compounds of carbon and hydrogen which are found so frequently in organic bodies.
The latter, when obtained for commercial purposes, bears the Indian name of caoutchouc.
This substance has long been known to the natives of both the Old and New World,
in Hindostan and South America. It was not, however, till the expedition of the French
Academicians to South America in 1735, that its properties and nature were made
known in Europe by a memoir upon it by M. de la Condamine. This notice excited
little attention; and subsequently notices of this substance were sent to the French
Academy, in 1751, by M. Fresnau, and in 1768 by M. Macquer. At the latter end of
the last century and the beglning of the present it was brought into this country in small
quantities, where, on account of its being used for rubbing out black-lead pencil marks, it
acquired the name of India-rubber. Although, after its application to the waterproofing
of garments, its consumption gradually increased, the importation into the United King-
dom in 1830 appears not to have been more than 50,000 pounds. In 1842, the import
of this article had increased to between 700,000 and 800,000 pounds. Up to the
present time the consumption of India-rubber has prodigiously increased; and one part
alone in South America is said now to send to Great Britain nearly 4,000 cwts. annually.
To the large consumption in the United Kingdom we must add that of America, where
the application of caoutchouc has been much more general and successful than even in
our own country.
The particular species of plants which are employed for procuring India-rubber are
very numerous, and it is probable that many yield it which are not yet known to botanists.
The tree which supplies most in continental India is the Ficus elastica, a tree belonging
to the order Moraceas; it is exceedingly abundant in Assam. All the species of ficus yield
caoutchouc to a greater or less extent iu their juices, and even the common fig (Ficus
carica) of Europe contains it. Species of ficus produce the caoutchouc brought from
Java, and F. radula, F. elliptica, and F. prinoides are amongst those mentioned as
affording a portion of that brought from America. Next to the MoraeeEe the order
Euphorbiacese yields the largest quantity of caoutchouc. The SzpAonia elastica, a plant
found in Guiana, Brazil, and extending over a large district of Central America,
yields the best kinds of India-rubber that are brought into the markets of Europe and
America. To another order, Apocynaceae, we are indebted for the caoutchouc which
is brought from the islands of the Indian Archipelago. The plant which is the source of
this substance in those districts is the Urceola elastica, a climbing plant of very rapid
growth and gigantic dimensions. A single tree is said to yield, by tapping, from fifty to
sixty pounds annually. Many other plants of this order yield caoutchouc, and of those
given on good authority we may mention Collophora utilis and Cameraria latifolia, plants
of South America; Vahea gummifera, in Madagascar; and Wittughbeia edulis -in the
East Indies. To this order belongs the cow tree, or Hya-hya (Taberncemonta utilis), of
tropical America, which yields a milky juice that is drunk by the natives of the district
in which it grows. The caoutchouc, whilst it is in the tissues of the plant, is evidently
in a fluid condition, but after its separation from the other fluid parts, its consistence
becomes changed, and it forms a solid mass similar, in its external characters, to vegetable
albumen. In this state it is dense and hard, but may be separated and rolled out so as
to form a sheet resembling leather. It has many interesting and peculiar properties.
Insoluble in water and in alcohol, it dissolves in ether, in the sulphuret of carbon, the
fat oils, and the liquid carburets of hydrogen. It is soft and elastic at the ordinary
temperature, but at the temperature of two degrees above the freezing point, it acquires
emulsions produced from seeds collects on the surface of the aqueous liquor, is, properly
speaking, a fatty body containing oxygen in its composition, as they all do; while the
kind of cream which swims upon the milky juice of the plants when left to itself, is one
of the compounds of carbon and hydrogen which are found so frequently in organic bodies.
The latter, when obtained for commercial purposes, bears the Indian name of caoutchouc.
This substance has long been known to the natives of both the Old and New World,
in Hindostan and South America. It was not, however, till the expedition of the French
Academicians to South America in 1735, that its properties and nature were made
known in Europe by a memoir upon it by M. de la Condamine. This notice excited
little attention; and subsequently notices of this substance were sent to the French
Academy, in 1751, by M. Fresnau, and in 1768 by M. Macquer. At the latter end of
the last century and the beglning of the present it was brought into this country in small
quantities, where, on account of its being used for rubbing out black-lead pencil marks, it
acquired the name of India-rubber. Although, after its application to the waterproofing
of garments, its consumption gradually increased, the importation into the United King-
dom in 1830 appears not to have been more than 50,000 pounds. In 1842, the import
of this article had increased to between 700,000 and 800,000 pounds. Up to the
present time the consumption of India-rubber has prodigiously increased; and one part
alone in South America is said now to send to Great Britain nearly 4,000 cwts. annually.
To the large consumption in the United Kingdom we must add that of America, where
the application of caoutchouc has been much more general and successful than even in
our own country.
The particular species of plants which are employed for procuring India-rubber are
very numerous, and it is probable that many yield it which are not yet known to botanists.
The tree which supplies most in continental India is the Ficus elastica, a tree belonging
to the order Moraceas; it is exceedingly abundant in Assam. All the species of ficus yield
caoutchouc to a greater or less extent iu their juices, and even the common fig (Ficus
carica) of Europe contains it. Species of ficus produce the caoutchouc brought from
Java, and F. radula, F. elliptica, and F. prinoides are amongst those mentioned as
affording a portion of that brought from America. Next to the MoraeeEe the order
Euphorbiacese yields the largest quantity of caoutchouc. The SzpAonia elastica, a plant
found in Guiana, Brazil, and extending over a large district of Central America,
yields the best kinds of India-rubber that are brought into the markets of Europe and
America. To another order, Apocynaceae, we are indebted for the caoutchouc which
is brought from the islands of the Indian Archipelago. The plant which is the source of
this substance in those districts is the Urceola elastica, a climbing plant of very rapid
growth and gigantic dimensions. A single tree is said to yield, by tapping, from fifty to
sixty pounds annually. Many other plants of this order yield caoutchouc, and of those
given on good authority we may mention Collophora utilis and Cameraria latifolia, plants
of South America; Vahea gummifera, in Madagascar; and Wittughbeia edulis -in the
East Indies. To this order belongs the cow tree, or Hya-hya (Taberncemonta utilis), of
tropical America, which yields a milky juice that is drunk by the natives of the district
in which it grows. The caoutchouc, whilst it is in the tissues of the plant, is evidently
in a fluid condition, but after its separation from the other fluid parts, its consistence
becomes changed, and it forms a solid mass similar, in its external characters, to vegetable
albumen. In this state it is dense and hard, but may be separated and rolled out so as
to form a sheet resembling leather. It has many interesting and peculiar properties.
Insoluble in water and in alcohol, it dissolves in ether, in the sulphuret of carbon, the
fat oils, and the liquid carburets of hydrogen. It is soft and elastic at the ordinary
temperature, but at the temperature of two degrees above the freezing point, it acquires