BALL VEIN

BALL VEIN, in mineralogy, a name given by the miners of Sussex to a sort of iron ore, common there, and wrought to considerable advantage. It yields not any great quantity of metal, but what it has runs freely in

Ball. in the fire; it is usually found in loose masses, not in the form of a stratum, and is often covered with one or more crusts. It generally contains some sparkling particles; and is usually of a circular form in the perfect masses, thickest in the middle, and gradually thinner as it approaches the sides. The ores of Sulfur in general are poor, but they require very little trouble in the working; so that a considerable profit is made annually from them.

Ball and Socket is an instrument made of brass, with a perpetual screw, so as to move horizontally, vertically, and obliquely; and is generally used for the managing of surveying and astronomical instruments.

Puff-Ball, the English name of the lycoperdon. See LYCOPERDON.

Martial Balls, in pharmacy, are a mixture of filings of iron and cream of tartar, formed into a solid consistence and form of a ball, which is used to impregnate water or other liquids with iron dissolved by the tartareous acid. To make these balls, one part of filings of iron and two parts powdered cream of tartar are mixed well together, and put into an earthen or iron vessel with some water. This mixture is to be stirred from time to time, till it becomes almost dry; and then it is to receive more water, and to be stirred as before. This treatment is to be continued till it acquires, when nearly dry, somewhat of the consistence and tenacity of softened rosin. Then it is to be rolled up in the form of a ball, which is generally kept tied up in a rag; and when intended to be used, it is to be infused in water, till it gives some colour to that liquid. The infusion of martial balls is tonic, vulnerary, discutient, and aperitive; and is employed both internally and externally*. Iron being soluble in all acids, is attacked in this preparation by the tartareous acid, which reduces it to a kind of neutral salt not crystallizable. This salt would remain liquid, and would form a soluble martial tartar, called tartarified tincture of Mars. If proper proportions of filings of iron and cream of tartar be used, and treated long enough for an entire and complete combination, nothing would be obtained but a liquor or magma, which could not be preferred in a solid form, but would be continually moist. Therefore, in the martial ball there is a good deal of the cream of tartar and filings of iron not combined together, by which its solidity is preserved.

Mercurial Balls, in pharmacy, are an amalgam of mercury and tin, sufficiently solid to be moulded, and to preserve a given form. The method of making them is by adding mercury to melted tin, and pouring the fluid mass into a round hollow mould.—These balls are employed to purify water, in which they are boiled; for which purpose travellers often carry some along with them. Nothing, however, can be more pernicious than such a practice, should the water contain any nitrous acid, which it very often does.

Balls of Silk Worms and Spiders, are little cases or cones of silk, wherein those insects deposit their eggs. Spiders are extremely tender of their balls, which they carry about with them, adhering to the papillæ about their anus. Grew mentions balls or bags of a species of silk worms in Virginia, as big as hens' eggs, and containing each four aurelias.

Zoologists speak of a sort of balls of hair covered

over with a smooth thin coat, or shell, found in the stomachs of oxen, cows, calves, horses, sheep, and goats. See the article BEZOAR.

Balls of Fire, in meteorology. See FIRE (Balls of).

Balls in electricity, are two pieces of cork, or pith of elder, nicely turned in a lathe to the size of a small pea, and suspended by fine linen threads; intended as electrometers, and of excellent use to discover small degrees of electricity, to observe the changes of it from positive to negative, and vice versa; and to estimate the force of a shock before the discharge, so that the operator should always be able to tell very nearly before the discharge, by knowing how high he has charged his jars, what the explosion will be.

Fire-Balls, are bags of canvas filled with gunpowder, sulphur, salt-petre, pitch, &c. to be thrown by the soldiers, or out of mortars, in order to fire the houses, incommoding trenches, advanced posts, or the like.—The Greeks had divers kinds of fire-balls, or πυρροβολιχίαι; one kind called, more particularly, πυρροβολιχίαι, made of wood, sometimes a foot or even a cubit long; their heads being armed with spikes of iron, beneath which were hemp, pitch, and other combustibles, which being set on fire, they were cast among the enemy. The preparations of fire-balls, among the moderns, consist of several operations, viz. making the bag, preparing the composition, tying, and, lastly, dipping the ball. 1. The bags for this purpose are either oval or round. 2. The composition wherewith fire-balls are filled is various: To ten pounds of meal gunpowder add two of salt-petre, one of sulphur, and one of colophony; or, to six pounds of gunpowder, add four of salt-petre, four of sulphur, one of powdered glass, half a pound of antimony, as much camphor, an ounce of sal-ammoniac, and four of common salt, all pulverised. Sometimes they even fill fire-balls with hand granadoes. 3. For tying the fire-balls, they prepare two iron rings, one fitted round the aperture, where the ball is to be lighted, the other near its base. A cord is tied to these rings in such a manner, as that the several turns represent femicircles of the sphere cutting the globe through the poles: over the cords, extended according to the length of the ball, others are tied, cutting the former at right angles, and parallel to each other, making a knot at each intersection: lastly, after putting in a leaden-bullet, the rest of the space is filled with tow or paper. 4. Thus completed, the fire-ball remains to be dipped in a composition of melted pitch four pounds, colophony two, and linseed oil or oil of turpentine two; after dipping, they cover it round with tow, and dip again, till it be brought to the just diameter required.

Light-Balls, are such as diffuse an intense light around; or they are balls which, being cast out of the hand or a mortar, burn for some time, and illuminate the adjacent parts. 1. Luminous or light-balls for the hand, are made of ground powder, salt-petre, brimstone, camphor, and borax, all sprinkled with oil, and moulded into a mass with fuet; and this is wrapped up in tow, with a sheet of strong paper over it. To fire it, they make a hole into it with a bodkin, into which they put some priming that will burn slow. Its use is to be cast into any works they would discover in the night-time. 2. For the larger light-balls, or these

those to be thrown to a greater distance, they melt equal quantities of sulphur, turpentine, and pitch; and herein dip an earthen or stone-ball, of a diameter much less than that of the mortar out of which the fire-ball is to be cast: then rolling it in gunpowder, and covering it round with gauze, they dip it again, and repeat the rest till it come to fit the cavity of the mortar: lastly, they sprinkle it around with gunpowder. This, being once kindled, will strongly illuminate all around the place where it is thrown, and give opportunity to examine the state and condition thereof.

Smoke or Dark Balls, those which fill the air with smoke, and thus darken a place to prevent discoveries. To prepare a darkening ball, make an oval or spherical bag, melt rosin over the coals; and add an equal part of saltpetre not purified, also of sulphur, and a fifth part of charcoal. The whole being well incorporated, put in tow first fired, and fill the bags with this composition, and dip it after the same manner as a fire-ball.

Stink-Balls, those which yield a great stench where fired to annoy the enemy. Their preparation is thus: Melt ten pounds of pitch, six of rosin, twenty of saltpetre, eight of gunpowder, and four of colophony; to these add two of charcoal, six of horse-hoofs cut small, three of assa-fœtida, one of stinking-faraeen, and any other offensive ingredients. The rest as in the former.

Sky-Balls, those cast on high out of mortars, and which, when arrived at their height, bursting like rockets, afford a spectacle of decoration. Sky-balls are made of a wooden shell, filled with various compositions, particularly that of the stars of rockets. These are sometimes intermixed with crackers and other combustibles, making rains of fire, &c.

Water-Balls, those which swim and burn a considerable time in the water, and at length burst therein. These are made in a wooden shell, the cavity of which is filled with refined saltpetre, sulphur, saw dust boiled in water of saltpetre, and dried; to which sometimes other ingredients are added, as iron filings, Greek pitch, amber dust, powdered glass, and camphor. The ingredients are to be ground, mixed up, and moistened with linseed oil, nut oil, olive oil, hempseed oil, or petrol. At the bottom is placed an iron coffin, filled with whole gunpowder, that the ball may at last burst with a greater noise; and, lastly, the ball is, by the addition of lead or otherwise, made of the same specific gravity with water.

Land-Balls are those which, being thrown out of a mortar, fall to the ground, burn, and burst there. The ingredients are much the same as in the water-balls, only the specific gravity is not attended to.