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like a Mosaic roof and pavement, supported with pillars of the same substance. In California there are large plains of it, and there are considerable mines of it near Cracow, in Poland. Bay Salt is produced from the evaporation of sea water by the heat of the sun only, and was so named from being first made in the Bay of St. Ubes, in Portugal. It is prepared in many parts of Europe, in America, &c.—Epsom Salts, so called from being originally extracted from the springs at Epsom, are used medicinally, and now principally obtained from the bittern; they contain sulphate and muriate of magnesia. Glauber Salts, or Sulphate of Soda, are procured by distilling common Salt with Sulphuric Acid. They are named after Glauber, a German, the discoverer. The decomposition of Salt furnishes muriatic acid, or spirit of salt (59). Salt is used in glazing pottery, and in some processes of dyeing ; also as a manure.

SALTPETRE, OR NITRE.

When the new chemical nomenclature was invented, by which substances are named from their component parts, the salt previously known only by the above titles, being a compound of potash and nitric acid, took the name of Nitrate of Potash. It occurs ready formed in the East Indies, from

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whence, in a state of moderate purity, the chief supply is procured. In Spain and elsewhere vast quantities are formed by nature. It may also be obtained artificially by submitting putrid animal and vegetable substances, mixed with calcareous earth, to the action of the atmosphere, but the process requires so much time, and is so productive, that it is never resorted to until all other sources are unavailable. Its uses are manifold; combined with sulphur and charcoal in various proportions, according to the use for which it is intended, it forms the article of its chief consumption-gunpowder. Hence the following lines from Shakspeare :

“ It was great pity, so it was,
That villanous Saltpetre should be digged
Out of the bowels of the harmless earth,
Which many a good tall fellow had destroyed
So cowardly.”

The Chinese are said to use two-thirds of the immense produce of the East Indies in making artificial fire-works, in the beauty and variety of wbich they are allowed to excel all other nations. The Greek fire, so dreadful in ancient warfare, was indebted to this substance, in combination with sulphur, resin, camphor, and other combustibles, for its destructive and inextinguishable nature. It is extensively used in metallurgy, in the manufacture of oil of vitriol, aquafortis, and other highly useful acids; added to salt it is commonly used in preserving meat, to which it gives the red hue; also in medicine. Roger Bacon mentions this salt under the name of Nitre in the 13th century.

SAGO

Is the pith of the Landan Tree growing in the East Indies and Moluccas, considered a great strengthener and restorative. The tree, which resembles a palm, grows spontaneously; the bark is about an inch thick, and covers long fibres interwoven with each other, which surround a kind of meal. When arrived at maturity, a period discovered by a white appearance upon the leaves, it is cut down near the root, and by being split into pieces, the Malays are easily enabled to procure this mealy substance, after which they dilute it with water and then strain it; this pulverized and reduced into granules, is sent to Europe and sold. The Indians eat this meal baked or boiled.

STEEL (see Iron).

SNUFF.

Snuff is tobacco in a powdered state, though other substances are generally added to give an

additional flavour, to suit the fancies of the takers. The Scotch and Irish Snuffs are most in repute, but a long catalogue of names might likewise be added. In making Snuff the leaves of the tobacco are further dried after arriving in this country, either pounded in a mortar or ground in a tobacco mill, and then sifted. The Irish toast their leaves and add the stalks.

SALEP.

A nutritious powder, prepared from the root of the Orchis, a plant growing naturally in some parts of England, but principally in Europe and Asia. It forms a considerable part of the diet of the inhabitants of Turkey, Syria, and Persia. The best time for gathering the roots is when the seed is formed and the stalk ready to fall, as the Salep is made of the new bulb which has then arrived at maturity.

SEPIA, OR CUTTLE, OR INK FISH.

A fish, principally noted for a bone contained in the body, which is chemically composed of calcareous matter, of an oval shape, and from its absorbent qualities frequently used as pounce. The structure inside is lamellated, and cellular-friable between the fingers. The outside appears entirely covered with an incrustation upon a horny substance, rendering it impervious to air or water. The bone is found upon most European shores, but very rarely the fish. By a power to fill the minute cells of the internal substance of this bone, it is supposed the fish is enabled to rise or sink at pleasure. When pursued by a fish of prey it throws out a black secreted fluid, by which the transparency of the surrounding water is destroyed, and which thus affords it means of escape.

“ Th' endanger'd Cuttle thus evades his fears,
And native hoards of fluid safety bears.
A pitchy ink peculiar glands supply,
Whose shades the sharpest beam of light defy ;
Pursu'd, he bids the sable fountains flow,
And, wrapt in clouds, eludes th' impending foe,
The fish retreats unseen, while self-born night

With pious shade befriends her parent's flight.” The famous Indian ink was formerly supposed to be a composition of this fluid, mixed with rice. The ancients wrote with it, hence its name of Ink Fish, and the following lines from Dryden's translation of Perseus :

“ But oh, what crosses wait on studious men!
The Cuttle's juice hangs clotted at our pen;
In all my life such stuff I never knew,
So gummy thick-dilute it, it will do.
Nay, now 'tis water!”

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