Part 8

We are informed by travellers, that some of the savage tribes eat steatite, either alone, or mixed with their food, to deceive hunger. The inhabitants of New Caledonia eat considerable quantities of it. Humboldt, the South American traveller, assures us that the Otomacks, a savage race of people, who live on the banks of the Orinoco, are almost wholly supported, during three months of the year, by eating species of steatite, or potter’s clay, which they first slightly bake, and then moisten with water. M. Golberry says that the negroes near the mouth of the Senegal mix their rice with a white kind of steatite, and eat it without inconvenience.

In some parts of Spain a variety of steatite is found, which is used by artists under the name of Spanish chalk. When slightly burned, this mineral is sometimes used as the basis of rouge.

125. FIGURE STONE _is a kind of steatite, which has, internally, a glimmering and resinous lustre, and a slaty or splintery fracture_.

From its softness, and yet solidity of texture, this mineral can easily be fashioned into various shapes, even with a knife. Hence in China, where it frequently occurs, it is cut into grotesque figures of various kinds, which the French call _magots de la Chine_, into cups, vases, pagodas, snuff─boxes, and other articles.

126. _MEERSCHAUM, or SEA─FROTH, is a singular kind of mineral, of yellowish or greyish white colour, sometimes so light as to float in water: when fresh dug it has nearly the consistence of wax._

_If exposed to a strong heat, it becomes so hard as to yield sparks with steel._

The principal use to which meerschaum is applied is in the formation of the bowls or heads of tobacco─pipes used by the Turks, and the quantity consumed for this purpose is very great. It is found in a fissure of grey, calcareous earth, about six feet wide, near Konie, in Natolia, where upwards of six hundred men are employed in the digging and preparation of it; and the sale of it supports a monastery of dervises established at that place. The workmen assert that it grows again in the fissure, and puffs itself up like froth. It is prepared for use by being first agitated with water in great reservoirs, then allowed to remain at rest for some time. The mixture soon passes into a kind of fermentation, and a disagreeable odour, resembling that of rotten eggs, is exhaled. As soon as this smell ceases, the mass is further diluted with water, which, after a while, is poured off. Fresh water is repeatedly added, until the mass is sufficiently washed and purified. The meerschaum, in this state, is dried to a certain degree. It is then pressed into a brass mould, and, some days afterwards, is hollowed out so as to form the head of the pipe. It is subsequently dried in the shade, and lastly is baked. In this state the pipe heads are brought to Constantinople, where they are subjected to further processes. They are first bailed in milk, and next in linseed oil and wax; and, when perfectly cool, are polished with rushes and leather. The boiling in oil and wax renders them capable of receiving a higher polish than could otherwise be given. When thus impregnated, they also acquire, by use, various shades of red and brown, which are thought to add considerably to their beauty. In Turkey, and even in Germany, meerschaum pipes that have been much used are more valued than those newly made, and this solely on account of the colouring they possess. Indeed there are people in those countries whose only employment consists in smoking tobacco pipes, until they acquire the favourite tints of colour. By long use, the heads become black: but if boiled in milk and soap, they are soon rendered white again.

It is asserted that the Turks spread meerschaum on bread, and eat it as a medicine; and that they cover with it the heads and eyes of dead bodies, previously to interment. As it lathers with water like soap, it is used by the Turkish women for washing their hair; and, as it absorbs oily matters, it is occasionally used, as fuller’s earth is with us, for the cleansing and scouring of cloth.

We are informed by Pliny, that a kind of bricks were made by the ancients, so light that, when dried, they would float in water. He describes them to have been formed of a spongy kind of earth, and to have had some resemblance to pumice stone, which he says might perhaps be applied to the same purposes as these bricks, if it could be obtained and wrought in sufficient quantity. Bricks of similar description have lately been made of a mineral substance found near Sienna, in Italy, and which is supposed to be meerschaum.

A kind of meerschaum has lately been discovered, in veins, in the serpentine (132) of Cornwall.

127. _BOLE is an earthy mineral, of yellowish or reddish brown colour, soft, and somewhat unctuous to the touch, and generally found in a massive state._

_It exhibits internally a glimmering lustre; and, when put into water, immediately absorbs it, and breaks down into small pieces with a crackling noise. This mineral is farther distinguished by its fracture being conchoidal, or appearing somewhat like the impression of a shell; and by its adhering strongly to the tongue._

Although bole is at present little used except as a basis of tooth powder, and a coarse kind of paint, it was formerly considered an important article in medicine, and used as an astringent. We are informed that tobacco pipes are sometimes made of this mineral; and that it is employed as an ingredient in the glaze of some kinds of earthen ware.

It is chiefly imported from the Levant; though it has also been found in considerable beds in Silesia and Saxony.

128. _LEMNIAN EARTH is a kind of bole of yellowish grey, or yellowish white colour, sometimes marbled with rust─like spots._

_It is distinguished from bole by being dry and not unctuous to the touch, dull internally, adhering slightly to the tongue, and its fracture being earthy._

With the ancients this mineral was considered an almost invaluable medicine. They procured it chiefly from Armenia, and the island of Lemnos, in the Grecian Archipelago. The Lemnian bole was held so sacred that it was dug in the presence of the priests of Venus, and, after having been mixed by them with goat’s blood, was moulded into cakes, which were impressed with the figure of a goat, to authenticate them. This done, it was administered as a consecrated remedy; and, even so lately as the sixteenth century, the vein of bole in Lemnos was annually opened on the sixth of August, and, after certain prayers by the priests, so much of the earth was taken out as was thought sufficient for the consumption of the ensuing year. The entrance was then closed, and the severest punishments were denounced against any one who should open it without permission. A portion of the earth was sent to Constantinople, where it was made into small cakes, and sealed by the ministers of the Emperor; the remainder was prepared in the island, and was impressed with the seal of the Governor. Not many years ago, it was customary with certain empirics on the Continent, to sell this substance in sealed packets, as a nostrum of great value, and particularly as possessing astringent properties of very extraordinary nature.

129. _FULLER’s EARTH is a well─known mineral, generally of greenish colour, more or less mixed with brown, grey, or yellow: of soft and almost friable texture, and somewhat unctuous to the touch._

_When put into water it immediately absorbs it, and breaks down into a fine pulp._

This earth is valuable for its property of taking grease out of woollen and other cloths, which, on a large scale, is effected by the operation called _fulling_, whence its name has been derived. This operation, which is performed by a kind of water mill, called a _fulling mill_, is particularly necessary with respect to new cloths, to extract from them the grease and oil that have been used in their preparation.

Fuller’s earth was formerly considered an article of such importance in England that its exportation was prohibited under severe penalties. It was then employed for most of those purposes for which soap has since been so extensively applied. In the dressing of cloth it is now so indispensable, that foreigners, although they can procure the wool, are never able, without fuller’s earth, to reach the perfection of the English cloths: and, in this country, incalculable quantities of it are consumed. As an article of domestic utility, it might be much more frequently used than it is, as a substitute for soap, in the cleaning and scouring of wooden floors and wainscots.

There are extensive beds of fuller’s earth in several of the counties of England. London is principally supplied from those of Kent, Sussex, and Surrey. At Wavedon, near Woburn, in Bedfordshire, a peculiarly fine kind is dug up from pits at the depth of ten or twelve feet below the surface of the ground; and no country in the world is known to produce fuller’s earth of quality so excellent as that obtained in England.

TALC FAMILY.

130. _JADE, or NEPHRITE, is a very hard and tough species of stone, of greenish or olive colour, somewhat unctuous to the touch, and looking as if it had imbibed oil._

_It is found massive, in blunt─edged or rounded pieces._

Nothing has so much tended to make this stone known, as a superstitious notion that a piece of it suspended to the neck will dissolve stones in the kidneys. Hence has been attained its appellation of nephrite, or divine stone; and hence have originated all those numerous amulets in the form of oval plates, hearts, fishes, birds, &c. pierced with holes for ribbons to pass through, which are seen in collections of the curious. Some of the Indian nations make talismans of jade.

From the roughness and tenacity of this stone, in addition to its hardness, it is very difficult to be cut and polished; and even the best polish which it is capable of taking as so imperfect, that a person ignorant of its nature might consider it to be merely smoothed and rubbed with oil. The ancient artists executed in it many beautiful and delicate figures; and it is impossible but to admire the industry and perseverance by which they produced even chains, and other hollow kinds of work, in jade.

The Turks cut it into handles for sabres and daggers, and into several kinds of vessels, to which they attach great value.

Jade occurs in granite (251) and gneiss (255) in Switzerland; but the most beautiful specimens of this mineral are brought from Persia, Egypt, and Siberia.

131. AXESTONE _is a kind of jade, but differs from it in having a slaty texture; and in being less transparent and less tough_. This stone is found in China, New Zealand, and on the banks of the river of Amazons, in America. And it is said that several of the tribes of American Indians form of it the axes which they use in place of iron. To explain how these people have been enabled to work a substance so rebellious as this is even to the file, and to other instruments of steel (of which they know not the use), it has been presumed that, when the stone is first taken from the earth, it is considerably less hard than when, by drying, its humidity is evaporated: that in this state they work it, and subsequently harden it, in some peculiar manner, by exposure to heat.

132. _SERPENTINE is a stone which, when polished, has a near resemblance to marble, is of dark green colour, or reddish; variously streaked, and spotted with lighter green, red, brown, and yellow._

_It is found in beds, and in a massive state; is translucent at the edges; and, when pounded, the powder feels soapy to the touch._

There are few stones likely to prove more valuable in ornamental architecture, both for beauty and durability, than this. It admits of an excellent polish, which is not easily injured by the effects of air or water. It is also too hard to suffer the same inconveniences of being scratched or broken as marble; and its colours are stated to be indestructible. And such is the size of many of the blocks of serpentine, that columns of almost any dimensions may be wrought out of them.

Of the serpentine obtained from the Island of Anglesea, and lately known by the name of _Mona marble_, a great proportion was sent to London by Messrs. Bullock and Co. who, until the death of Mr. Bullock, had a large warehouse and polishing rooms for it in Oxford─street. The prevailing colours of this stone are red and green. The quarries were worked by them to considerable extent. They manufactured it into chimney pieces, slabs, columns, and other articles; and its great beauty, and its excellence, in many respects, over the generality of marbles, will recommend it strongly to the public notice.

The chief places in which serpentine has hitherto been found are near Bareuth, and Zöblitz, in Saxony; in some districts of Cornwall; about six miles west of the Paris copper mine, in the island of Anglesea; at Portsoy, in Bamffshire, and other parts of Scotland; and at Cloghan Lee, in the county of Donegal, Ireland.

At Zöblitz there are some extensive manufactories, in which serpentine is made into vessels and ornaments of various shapes, that are carried for sale over nearly all parts of Germany. Several hundred persons are there employed in the working of this stone.

The name of serpentine is derived from some of the varieties appearing coloured and spotted like a serpent’s skin. This stone, when found intermixed with primitive limestone, or crystalline white marble, differs in no respect from the celebrated _verde antique_ marble (149).

133. _POTSTONE, or LAPIS OLLARIS, is a greenish grey stone, unctuous to the touchy and so soft when first taken from the quarry as to yield to the pressure of the nail, yet not easily broken._

_It is found in a massive state._

In consequence of the softness and tenacity of this stone, it can be turned upon a lathe, and otherwise cut and wrought with great ease. Hence, in Egypt, Lombardy, Norway, and other countries where it is found, it is formed into various kinds of culinary vessels and lamps, which harden in drying, and are capable of withstanding the strongest action of fire. Vessels of this description were known to the ancients; and are particularly mentioned by Pliny, the Roman naturalist, who speaks of some that were highly wrought being very valuable.

Potstone is used in some countries for the lining of stoves, furnaces, and ovens; and it is so durable as to have, in some instances, stood unimpaired for several hundred years.

On the banks of the Lake Como, there were some extensive quarries of potstone, which had been worked from the beginning of the Christian era. These quarries, however, fell in, on the 25th of August, 1618, and destroyed the neighbouring town of Pleurs; which had previously obtained by means of them an annual revenue of about sixty thousand ducats.

134. _COMMON, or VENETIAN TALC, is an earthy stone, capable of being divided into plates or leaves, which are soft and unctuous to the touch, somewhat transparent, and usually of greenish silvery white colour._

_It leaves a white trace when rubbed upon any object._

_Mica and talc have a near resemblance to each other; but the plates of the former, when bent, are elastic, while those of the latter are not._

Venetian talc is very abundant in the Tyrol and the Valteline. In a state of powder it renders the skin soft and shining; a property which appears to have suggested the idea of employing it as the basis of the cosmetic named _rouge_. This is prepared by rubbing together, in a warm mortar, certain proportions of carmine, or extract of the flowers of _carthamus tinctorius_, with finely powdered talc, and a certain portion of oil of benzoin.

The Romans prepared a beautiful blue or purple colour, by combining pounded talc with the colouring fluid of some particular kinds of testaceous animals, that are found among the submarine rocks of the coasts of the Mediterranean. According to Tavernier, the French traveller, the Persians whiten the walls of their houses and gardens with lime, and then powder them with a silvery white kind of talc; which, he says, gives to them a very beautiful appearance. Talc is now used by the Chinese, and was formerly used by the Europeans, in medicine,

135. _INDURATED TALC, or FRENCH CHALK, is a heavy mineral, of close texture, and generally of greenish grey colour; unctuous to the touch, and having a somewhat slaty fracture._

_It is found in a massive state; and leaves a white trace when rubbed upon any object._

This is a well known substance, which is in great request by carpenters, tailors, hat─makers, and others, as the lines that are drawn with it are not so easily effaced as those that are made with chalk, and particularly as they remain unaltered even under water. If lines be traced with it on glass, they remain invisible, or at least are scarcely perceptible by the naked eye, till breathed upon. This, it has been conjectured, in part depends on the comparative softness of the substance with which the impression is made; the condensation of the breath taking place more readily on the glass than on the talc that covers it, and the impression of the talc becoming more apparent by the contrast.

Indurated talc, when reduced to powder, is frequently employed for the purpose of removing stains, occasioned by grease, from silk and cloth. This it does effectually, and, in general, without injuring even the most delicate colour. Like potstone, it is sometimes manufactured into culinary vessels.

This mineral is found in several parts of the continent of Europe; and in Cornwall, Scotland, and the Shetland Islands.

136. _ASBESTOS is a greenish or silvery white mineral, of fibrous texture, which is found in many mountainous countries of the Continent, in the island of Anglesea, and in Scotland. It occurs in shapeless masses, and varies much both in weight and hardness._

The name of asbestos is derived from the Greek language, and signifies that which is inconsumable. This mineral, and particularly a silky variety of it, in long slender filaments, called _amianthus_, was well known to the ancients. They made it into an incombustible kind of cloth, in which they burned the bodies of their dead, and, by which means, they were enabled to collect and preserve the ashes without mixture. In the manufacture of this article they were not able to weave the asbestos alone; but, in the loom, were obliged to join with it linen or woollen threads, which were afterwards burned away.

Incombustible cloth was purchased by the Romans at an enormous expense. Sir J. E. Smith, when at Rome, saw a winding sheet of amianthus in the Museum of the Vatican. It was coarsely spun, but as soft and pliant as silk. The person who attended him set fire to one corner of it; and the same part burned repeatedly with great rapidity and brightness, without being at all injured. This interesting relic was discovered, in the year 1702, in a funeral urn, and contained burned bones, together with a quantity of ashes. It was nine Roman palms long, and about seven in width, and had been deposited in the library of the Vatican by order of Pope Clement the Eleventh.

Cloth made of amianthus, when greased, or otherwise contaminated with dirt, may be cleansed by throwing it into a bright fire. In this process the stains are burned out, and the cloth is restored to a dazzling white colour. Pliny, the Roman naturalist, informs us that he had himself seen table─cloths, towels, and napkins of amianthus taken from the table of a great feast, thrown into the fire, and burned before the company: and by this operation, he says, they became better cleansed than if they had been washed.

The inhabitants of some parts of Siberia manufacture gloves, caps, and purses of amianthus; and in the Pyrenees it is wrought into girdles, ribbons, and other articles. The finest girdles are made by weaving the most beautiful and silky filaments with silver wire. These are much prized by the women, not only on account of their beauty, but from certain mysterious properties they are supposed to possess.

The shorter fibres of amianthus have sometimes been manufactured into paper, but this is too hard for use. It has, indeed, been proposed to preserve valuable documents from fire, by writing them on paper made of amianthus. Such a plan might deserve consideration, if we possessed fire─proof ink; but until this be obtained, the fire─proof paper will be of little use.

When several of the long fibres of this mineral are placed together, they may be formed into wicks for lamps; and it has been asserted that such wicks are incombustible. Kircher, the German philosopher, had a wick made of amianthus which burned for two years without injury, and was at last destroyed by accident. It is said that the inhabitants of Greenland make use of amianthus for the wicks of their lamps.

This substance, although it will long continue unaltered in considerable heat, yet if the heat be much increased it ceases to withstand it, and is melted into a dense kind of scoria. In the island of Corsica asbestos is advantageously employed in the manufacture of pottery. Being reduced into fine filaments, it is kneaded with clay; and vessels made of this mixture are said to be lighter, less brittle, and more capable of sustaining sudden alterations of heat and cold than common earthenware.

CHRYSOLITE FAMILY.

137. _CHRYSOLITE, or PERIDOT, is a soft gem, usually of yellowish green colour, though sometimes it is grass─green, or bluish green, but with a tinge of brown._

_It is generally found in fragments and rounded pieces, and rarely crystallized. In the latter case its regular form is an eight, ten, or twelve─sided prism._

Though scarcely harder than glass, and consequently inferior to most other gems in lustre, these stones are not unfrequently used in jewellery, particularly for necklaces and ornaments for the hair; and, when well matched in colour, and properly polished, their effect is very good. They are, however, too soft for ring stones; for, by wearing, they soon become dull on the surface. But it is said that their lustre may, in some degree, be restored by immersing them in olive oil.

To give the greatest brilliancy to this stone, we are informed by Mr. Mawe, that a copper wheel is used, on which a little sulphuric acid, or spirit of vitriol (24), is dropped; and that, during the process, an highly suffocating odour is given out. But he is of opinion that the most advantageous way of working it would be that in which glass is cut.

Chrysolite is imported from the Levant, and is said to be found in Upper Egypt, and on the shores of the Red Sea.

BASALT FAMILY.

138. _BASALT is a greyish black and coarse grained stone, which is usually found either in globular distinct pieces or in groups of large columns, each of which has from three to eight sides, and is divided horizontally into numerous stones, that very exactly lie upon, or fit into each other._

The most remarkable assemblages of basaltic columns that are known are those called the _Giants’ Causeway_, on the coast of Antrim, in Ireland, and the _Cave of Fingal_, in the island of Staffa, one of the Hebrides, or Western Islands of Scotland.

The former, which is believed by the common people to have been an artificial production, the vast labour of giants who formerly inhabited the country, consists of an irregular group of many thousand jointed pillars. Most of these are of considerable height; are in general five─sided, fifteen or sixteen inches in diameter, and each perfectly distinct from top to bottom, though so closely and compactly arranged that it is scarcely possible to introduce any thing betwixt them. This assemblage of columns extends into the sea to a distance unknown, and along a tract of the sea coast of nearly six miles.