_QUEER RELATIONS: THE CAOUTCHOUC AND THE MILK TREE_.
"What dark, strange-looking trees!" exclaimed the children while looking
at an illustration of caoutchouc trees in Brazil. "How thick and strong
they are! And what funny tops!--like pointed umbrellas."
"The India-rubber tree is not likely to be mistaken for any other," said
their governess, "and it does not look very dark and gloomy in that
forest, where everything seems to be crowded close and in a tangle,
because South American vegetation grows so thickly and rapidly. This is
the country which supplies the largest quantity of India-rubber. Immense
cargoes are shipped from the town of Para, on the river Amazon, and
obtained from the _Siphonia elastica_."
"Are the stems all made of India-rubber?" asked Edith, who thought that
was exactly what they looked like.
"Are the stems of the maple trees made of maple-sugar?" replied Miss
Harson. "The India-rubber is got from its tree as the sugar is from the
maple tree. It is taken from the trunk in the shape of a very thick
milky fluid, and it is said that no other vital fluid, whether in animal
or in plant, contains so much solid material within it; and it is a
matter of surprise that the sap, thus encumbered, can circulate through
all the delicate vessels of the tree. Tropical heat is required to form
the caoutchouc; for when the tree is cultivated in hothouses, the
substance of the sap is quite different. The full-grown trees are very
handsome, with round column-like trunks about sixty feet high, and the
crown of foliage is said to resemble that of the ash."
"Did people always know about India-rubber?" asked Clara.
"No indeed! It is not more than a hundred and fifty years--perhaps not
so long--since it was a great curiosity; so that a piece half an inch
square would sell in London for nearly a dollar of our money, but now it
comes in shiploads, and a pound of it costs less than quarter of that
sum. It is used for so many purposes that it seems as if the world could
never have gone on without it. All sorts of outside garments to keep out
the rain are made of it. Waterproof cloaks are called macintoshes in
England because this was the name of the person who invented them.
India-rubber is also used for tents and many other things, and, as water
cannot get through it, there is a great saving of trouble and expense."
"It must be splendid for tents," said Malcolm; "no one need care, when
snug under cover, whether or not it rained in the woods."
"People do care, though," was the reply, "for they expect, when in the
woods, to live out of doors; but the India-rubber is certainly a great
improvement on tents that get soaked through."
"I like it," said Edith, "because it rubs things out. When I draw a
house and it's all wrong, my piece of India-rubber will take it away,
and then I can make another one on the paper."
"That is the very smallest of its uses," replied Miss Harson, smiling at
the little girl's earnestness, "and yet we find it a great convenience.
An English writer, speaking of it when it was first known in England,
said that he had seen a substance that would efface from paper the marks
of a black-lead pencil, and he thought it must be of use to those who
practiced drawing."
"How funny that sounds!" exclaimed Malcolm. "Why, I couldn't get along
without my India-rubber when I make mistakes,"
"You might," said his governess, "if you had some stale bread to rub
with; for people _have_ gotten along without a great many things which
they now think necessary."
"Miss Harson," said Clara, "won't you tell us, please, how they get the
caoutch--whatever it is--and make it into India-rubber?"
"I will," was the laughing reply, "when you can say the word properly.
C-a-o-u-t-c-h-o-u-c--koochook."
As Clara said, Miss Harson made things so easy to understand! and in a
very short time the hard word was mastered.
"As I have never seen the sap gathered," continued the young lady, "I
shall have to read you an account of it, instead of telling you from my
own experience; but the description is so plain that I think we shall
all be able to understand it very well: 'At certain seasons of the year
the natives visit some islands in the river Amazon that for many months
are covered with water. As soon as the water subsides and a footing can
be obtained the Indians arrive in parties, to seek for the trees. The
Indian who comes every morning to collect the juice from the trunk has a
number of trees allotted to him, and goes the round of the whole. The
previous night he has made a long, deep cut in the bark of each and hung
an earthen vessel beneath, to receive the thick, creamlike substance
that trickles down. The vessel is filled by morning, and he pours the
contents into one much larger and carries it to his hut. He is provided
with a number of moulds of different shapes and sizes, and he dips them
into the juice and puts them aside to dry. They are then dipped again,
and the process is continued until the coat of India-rubber on the mould
is of sufficient thickness. It is made black by passing it through the
smoke of burning palm-nuts. The moulds are broken and taken out, leaving
the India-rubber ready for sale, and pretty much as we used to see it in
the shops before the people of this country had learned how to
work it.'"
"That seems easy enough," said Malcolm, "but how do they make it into
gutta-percha?"
"Gutta-percha is not made," replied his governess, "and it is taken from
an entirely different tree, the _Icosandra gutta_, which grows in
Southern Asia. The milky fluid is procured in the same way, but it is
placed in vessels to evaporate, and the solid substance left at the
bottom is the gutta-percha. It is not elastic, like India-rubber, and
is called 'vegetable leather' because of its toughness and leathery
appearance. It was discovered by an English traveler a long time before
it was supposed to have any useful properties, but now it is considered
a very valuable material. The wonderful submarine telegraph could not
convey its messages between the Old World and the New were not its wires
protected from injury by a coating of gutta-percha. Its unyielding
nature and its not being elastic render it the very material needed. The
long straps used in working machines are also made of gutta-percha, and
this is another instance where its non-elasticity gives it the
preference over India-rubber."
"And what is vulcanite?" asked Clara.
"It is caoutchouc mixed with sulphur. Unless a small quantity of
brimstone is added in the manufacture of overshoes, they become soft
when exposed to heat and hardened when exposed to cold; but it was
discovered that the sulphur will keep them from being affected by
changes in temperature. When a large amount of sulphur is used, the
India-rubber, becomes as hard as horn or wood, and this is the substance
called vulcanite. Now the gum is imported in masses, to be wrought over
by our skillful mechanics."
The children were very much pleased to find that they had learned the
nature of three important articles--India-rubber, gutta-percha and
vulcanite--and they thought it would be quite easy to remember the
differences between them.
"And now," said Miss Harson, "the last of these useful trees--the cow
tree, or milk tree--is the most curious one of all. Like the caoutchouc,
it is a native of South America; but the sap is a rich fluid that
answers for food, like milk. It is a fine-looking tree with oblong,
pointed leaves about ten inches in length and a fleshy fruit containing
one or two nuts. The sap is the most valuable part; and when incisions
are made in the trunk of the tree, there is an abundant flow of thick
milk-like sap, which is described as having an agreeable and balmv
smell. The German traveler Humboldt drank it from the shell of a
calabash, and the natives dip their bread of maize or cassava in it.
This milk is said to be very fattening; and when exposed to the air, it
thickens into a substance which the people call cheese."
"Milk and cheese from a tree!" exclaimed Malcolm. "Do you think we'd
like them as well as ours, Miss Harson?"
"No," was the reply, "I do not think we should; but if we had never
known any other kind, it would be quite a different matter, and the
traveler says that both smell and taste are agreeable. The sap, it
seems, is like curdled milk, and the natives say that they can tell,
from the thickness and color of the foliage, the trunks that yield the
most juice. This wonderful tree will be found growing on the side of a
barren rock, and its large, woody roots can scarcely penetrate into the
stone. For several months of the year not a single shower moistens its
foliage. Its branches then appear dead and dried; but when the trunk is
pierced, there flows from it a sweet and nourishing milk. It is at the
rising of the sun that this vegetable fountain is most abundant. The
negroes and natives are then seen hastening from all quarters, furnished
with large bowls to receive the milk, which grows yellow and thickens at
its surface. Some empty their bowls while under the tree itself; others
carry the juice home to their children."
"Isn't it funny," said Edith, laughing, "to go and get their breakfasts
from a _tree_? I wish we had some milk trees here."
"But you would not find it pleasant," replied their governess, "to have
some other things that are always found where the milk tree grows. The
intense heat and the swarms of mosquitoes and biting flies, the serpents
and jaguars and other disagreeable and dangerous creatures, make life in
that region anything but pleasant, and the curious vegetation and
delicious fruits are not worth the suffering inflicted by all these
torments."
On hearing of these drawbacks the children soon decided that their own
dear home was the best, and no longer envied the possessors even of
the cow tree.