A Catechism of Familiar Things Part 26

How is the Caoutchouc obtained from the Tree?

By making incisions in the trunk of the tree, from which the fluid resin issues in great abundance, appearing of a milky whiteness at first, but gradually becoming of a dark reddish color, soft and elastic to the touch.

To what use is this substance put?

The Indians make of it boots, shoes, bottles, flambeaux, and a species of cloth. Amongst us it is combined with sulphur, forming the vulcanized rubber of commerce, which is used for many purposes. A greater proportion of sulphur, produces vulcanite, a hard black substance, resembling jet.

_Flambeaux_, torches burnt to give light.

What is Sponge?

A marine substance, found adhering to rocks and sh.e.l.ls under the sea-water, or on the sides of rocks near the sh.o.r.e. Sponge was formerly imagined by some naturalists to be a vegetable production; by others, a mineral, or a collection of sea-mud, but it has since been discovered to be the fabric and habitation of a species of worm, or polypus.

What do you mean by Polypus?

A species of animals called Zoophytes, by which are meant beings having such an admixture of the characteristics of both plants and animals, as to render it difficult to decide to which division they properly belong. They are animal in substance, possessed indeed of a stomach, but without the other animal characteristics of blood-vessels, bones, or organs of sense; these creatures live chiefly in water, and are mostly incapable of motion: they increase by buds or excrescences from the parent zoophyte, and if cut off will grow again and multiply; each part becoming a perfect animal. Myriads of the different species of zoophytes reside in small cells of coral, sponge, &c., or in forms like plants, and multiply in such numbers as to create rocks and whole islands in many seas, by their untiring industry. Polypus signifies having many feet, or roots; it is derived from the Greek.

_Myriads_, countless numbers.

Whence are the best and greatest number of Sponges brought?

From the Mediterranean, especially from Nicaria, an island near the coast of Asia: the collection of sponges forms, in some of these islands, the princ.i.p.al support of their inhabitants. They are procured by diving under water, an exercise in which both men, women, and children are skilled from their earliest years. The fine, small sponges are esteemed the best, and usually come from Constantinople; the larger and coa.r.s.er sorts are brought from Tunis and Algiers, on the coast of Africa. Sponge is very useful in the arts, as well as for domestic purposes.

What is Coral?

A substance which, like sponge, was considered as a vegetable production, until about the year 1720, when a French gentleman of Ma.r.s.eilles commenced (and continued for thirty years,) a series of observations, and ascertained that the coral was a living animal of the Polypus tribe. The general name of zoophytes, or plant animals, has since been applied to them. These animals are furnished with minute glands, secreting a milky juice; this juice, when exuded from the animal, becomes fixed and hard.

_Series_, a course or continued succession.

_Glands_, vessels.

_Exuded_, from exude, to flow out.

Is this substance considered by naturalists as the habitation of the Insect?

Not merely as the habitation, but as a part of the animal itself, in the same manner that the sh.e.l.l of a snail or an oyster is of those animals, and without which they cannot long exist. By means of this juice or secretion, the coral insects, at a vast but unknown depth below the surface of the sea, attach themselves to the points and ridges of rocks, which form the bottom of the ocean; upon which foundation the little architects labor, building up, by the aid of the above-mentioned secretion, pile upon pile of their rocky habitations, until at length the work rises above the sea, and is continued to such a height as to leave it almost dry, when the insects leave building on that part, and begin afresh in another direction under the water. Huge ma.s.ses of rocky substances are thus raised by this wonderful little insect, capable of resisting the tremendous power of the ocean when agitated to the highest pitch by winds or tempests.

_Architect_, one who builds.

How do these Coral Rocks become Islands?

After the formation of this solid, rocky base, sea-sh.e.l.ls, fragments of coral, and sea-sand, thrown up by each returning tide, are broken and mixed together by the action of the waves; these, in time, become a sort of stone, and thus raise the surface higher and higher; meanwhile, the ever-active surf continues to throw up the sh.e.l.ls of marine animals and other substances, which fill up the crevices between the stones; the undisturbed sand on its surface offers to the seeds of trees and plants cast upon it by the waves, a soil upon which they rapidly grow and overshadow the dazzling whiteness of the new-formed land. Trunks of trees, washed into the sea by the rivers from other countries and islands, here find a resting-place, and with these come some small animals, chiefly of the lizard and insect tribe.

Even before the trees form a wood, the sea-birds nestle among their branches, and the stray land-bird soon takes refuge in the bushes. At last, man arrives and builds his hut upon the fruitful soil formed by the corruption of the vegetation, and calls himself lord and master of this new creation.

_Surf_, the white spray or froth of the sea waves.

Where is the Coral Insect found?

In nearly all great seas; but particularly in the Mediterranean, where it produces Corallines of the most beautiful forms and colors: it is in the Pacific Ocean, however, where these tiny workmen are effecting those mighty changes, which exceed the most wonderful works of man.

What is that part of the Pacific called, where the Coral Rocks are most abundant?

The Coral Sea, from the number of coral reefs and sunken islands, with which it abounds; it includes a region of many miles in extent, the whole of which is studded with numberless reefs, rocks, islands, and columns of coral, continually joining and advancing towards each other. All navigators who have visited these seas, state that no charts or maps are of any service after a few years, owing to the number of fresh rocks and reefs which are continually rising to the surface. The wonderful instinct of these animals leads them to continue working without ceasing, until their labors are finished, or their lives extinct.

_Reef_, a chain or line of rocks lying near the surface of the water.

_Extinct_, at an end, dead.

What are the names of the princ.i.p.al islands of Coral formation?

The New Hebrides, the Friendly Isles, the Navigator's Isles, the Society Islands, the Marquesas, the Gambier group, and others. These groups are separated from each other by channels or seas, wider than those which divide the individual islands which form the respective groups; but all these waters abound with shoals and minor islets, which point out the existence of a common base, and show that the work by which they will afterwards be united above the level of the sea is continually going forward.

_Shoals_, shallows; places where the water is of little depth.

_Minor_, less, smaller than others.

_Existence_, being.

What is a singular characteristic of the Coral Islands?

On all of them a plentiful supply of sweet and fresh water may be obtained by digging three or four feet into the coral; and even within one yard of high-water mark such a supply is to be found. They are mostly covered with a deep rich soil, and well wooded with trees and evergreens of different kinds. These islands vary in extent, as well as in the degree of finish to which they have arrived; some of the largest being about 30 miles in diameter, and the smallest something less than a mile;--all of various shapes, and all formed of living coral.

_Diameter_, a straight line through the middle of a circle.

Is Coral put to any use by man?

White Coral, which is nowhere so abundant as about the sh.o.r.es of Ceylon, and others of the neighboring Indian coasts, is employed as lime by the inhabitants of that part of the world, for building houses, &c., by burning it after the manner of our lime. This coral lies in vast banks, which are uncovered at low water. Coral, particularly the beautiful red sort, is likewise made into various ornaments, as necklaces, &c.

Of what is our Lime composed?

Of a useful earth, which absorbs moisture and carbonic acid, and exists as limestone, or in marble and chalk, which, when burnt, become lime: in its native state it is called carbonate of lime, and is burnt to disengage the carbonic acid; when made into a paste, with one part water and three parts lime,[13] and mixed with some other mineral or metallic substances, it forms plastic cements and mortars; and afterwards, imbibing carbonic acid from the atmosphere, it becomes again carbonate of lime, as hard as at first; and hence its use in building.

[Footnote 13: See Chapter XVI., article Lime.]

_Plastic_, yielding, capable of being spread out or moulded.