raging, stepped to a side-table for an iron to take the digester out of the fire, when it suddenly burst with the explosion of a musket. It was heard at a considerable distance, and actually shook the house. The bottom of the vessel that was in the fire gave way; the blast of the expanded water blew all the coals out of the fire into the room, the remainder of the vessel flew across the room, and, hitting the leaf of an oak table, an inch thick, broke it all in pieces, and rebounded half the length of the room back again. He could not perceive the least sign of water, though he looked carefully for it; the fire was quite extinguished, and every coal black in an instant.

The following accident was attended with more fatal consequences.

A steam-engine was repairing at Chelsea, and, as the workmen were endeavouring to discover the defect, the boiler suddenly exploded, and, a cloud of steam rushing out at the fracture, struck one of the men who was near it, like a blast of lightning, and killed him in a moment; when his companions endeavoured to take off his clothes, the flesh came off with them from the bones.

This glass

MR. DE TSCHIRNHAUSEN constructed a burning-glass, between three and four feet in diameter, and whose focus was rendered more powerful by a second one. melted tiles, slates, pumice-stone, &c., in a moment; pitch, and all resins, were melted even under water; the ashes of vegetables, wood, and other matters, were converted into glass; indeed, it either melted, calcined, or dissipated into smoke, every thing applied to its focus.

Mr. Parker, of Fleet-street, made a burning-glass, three feet in diameter; it was formed of flint glass, and when on its frame, exposed a surface of 2 feet 8 inches to the solar rays. It had a small glass fitted to it, to converge the rays, and heighten the effect. The experiments made by it were more powerful and accurate than those performed

by any other glass. The following is a brief epitome of its astonishing power.

Substances melted, with their weight; and Weight Time the Time in Seconds, which they took in

melting.

in

in

Grains. Seconds.

Fulminating Powder.

THIS powder is made by rubbing together, in a hot marble mortar, with a wooden pestle, three parts, by weight, of nitre, two of mild vegetable alkali, and one of flowers of sulphur, till the whole is accurately mixed. If a drachm of this powder be exposed to a gentle heat, in an iron ladle, till it melts, it will explode with a noise as loud as the report of a cannon.

A more powerful fulminating Powder.

THE most wonderful instance of chemical detonation is formed by the combination of volatile alkali with silver. Gunpowder, or fulminating gold, are not to be compared with this invention, and the great danger attending its manufacture prevents us from giving a methodical account of its preparation to our readers, particularly as it can be purchased, properly prepared, of the chemists.

The slightest agitation or friction is sufficient to cause its explosion. When it is once obtained, it can no longer be touched with safety. The falling of a few atoms of it, from a small height, produces an explosion; a drop of water falling on it has the same effect. No attempt, therefore, can be made to enclose it in a bottle, but it must be let alone in the capsule, wherein, by evaporation, it obtains this terrible property. To make this experiment with safety, no greater quantity than a grain of silver should be used; the last process of drying should be made in a metallic vessel, and the face of the operator defended by a mask with strong glass eyes.

To make the Phosphorus Match Bottles.

NOTHING more is necessary for this purpose, than to drop small pieces of dry phosphorus into a common phial; gently heat it till it melts; and then turn the bottle round, that it may adhere to the sides. The phial should be closely corked; and when used, a brimstone match is to be introduced, and rubbed against

common

the sides of the phial; this inflames the match when it is brought out of the bottle. Though there is no danger in phosphorus, till friction, or fire, is applied, yet persons cannot be too cautious in the use of it, as instances have been known of one of these bottles catching fire in the pocket, and very much endangering the person who carried it; likewise, if carelessly used, small particles are apt to get under the nails, or on the hand; and if, by accident, they are held to the fire, or rubbed together, a flame will presently kindle.

To make a Ring suspend by a Thread, after the Thread has been burned.

SOAK a piece of thread in urine, or common salt and water. Tie it to a ring, not larger than a wedding ring. When you apply the flame of a candle to it, it will burn to ashes, but yet sustain the ring.

To form Figures in relief on an Egg.

DESIGN on the shell any figure or ornament you please, with melted tallow, or any other fat oily substance; then immerse the egg into very strong vinegar, and let it remain till the acid has corroded that part of the shell which is not covered with the greasy matter: those parts will then appear in relief, exactly as you have drawn them.

To give a ghastly Appearance to Persons in a

Room.

DISSOLVE salt in an infusion of saffron and spirits of wine. Dip some tow in this solution, and, having set fire

to it, extinguish all the other lights in the room.

To change Blue to White.

DISSOLVE Copper fillings in a phial of volatile alkali; when the phial is unstopped, the liquor will be blue; when stopped, it will be white.

Magical Transmutations.

INFUSE a few shavings of logwood in common water, and when the liquor is sufficiently red, pour it into a bottle. Then take three drinking-glasses, and rinse one of them with strong vinegar; throw into the second a small quantity of pounded alum, which will not be observed, if the glass has been recently washed, and leave the third without any preparation. If the red liquor in the bottle be poured into the first glass, it will appear of a straw colour; if into the second, it will pass gradually from blueish-grey to black, when stirred with a key, or any piece of iron, which has been previously dipped in strong vinegar. In the third glass, the red liquor will assume a violet tint.

To make Pomatum with Water and Wax.

WATER and wax are two substances that do not naturally unite together; therefore, to those who witness the following process, without knowing the cause, it will have the appearance of marvellous. Put into a new glazed earthen pot, six ounces of river water and two ounces of white wax, in which you must previously conceal a strong dose of salt of tartar. If the whole be then exposed to a considerable degree of heat, it will assume the consistence of pomatum, and may be used as such.

Iron transformed into Copper.

DISSOLVE blue vitriol in water, till the water is well impregnated with it; and immerse into the solution small plates of iron, or coarse iron filings. These will be at tacked and dissolved by the acid of the vitriol, while the copper naturally contained in the vitriol will be sunk and deposited in the place of the iron dissolved. If the piece of iron be too large for dissolving, it will be so completely covered with particles of copper, as to resemble that metal itself.