Method of distinguishing Iron from Steel.

Drop a little weak aqua-fortis on the metal; let it remain for a few minutes, and then wash it off with If it is steel, the spot will be black, but if iron, the spot will be whitish grey.

water.

A Test for discovering the presence of Lead,
Copper, &c. in Wines.

Lead and copper being sometimes used to amend the taste of wines, and these metals being of a very poisonous quality, a test that shall detect this is of great value. The following test is the discovery of Mr. Hanhemann.

Equal parts of oyster shells and crude sulphur are to be kept in a white heat for a quarter of an hour, and, when cold, this is to be mixed with an equal quantity of acidulous tartrite of potash, and put into a strong bottle with common water for an hour, and then decanted into bottles holding an ounce each, with twenty drops of muriatic acid

in each.

This liquor precipitates the least quantities of lead, copper, &c. from wines, in a very sensible black precipitate.

To make Pearl White.

Put some good aqua-fortis into a Florence flask, and gradually add to it bismuth broken into small pieces, till no more dissolves; then let the solution remain till it is transparent. Add to this some

water, and a white precipitate will be formed, which is to be washed and dried. This is white oxyde of bismuth, commonly termed magistery of bismuth, or pearl-white.

This is used as a cosmetic, and is sold by the perfumers; but it very much impairs the skin, blackening it by degrees, so that once used, it must be continued; and it is also to be feared, that it has, besides, deleterious effects upon the constitution.

To procure Animalcula for the Microscope...

The surface of infused liquors is generally covered with a thin pellicle, which is easily broken, but acquires thickness by standing; the greatest number of animalculæ are generally to be found in this superficial film.

To make an infusion of pepper.-Cover the bottom of an open jar, about half an inch thick, with common black pepper, bruised; pour as much soft water in the vessel as will rise about an inch above the pepper. The pepper and water are then to be well shaken together; after which they must not be stirred, but be left exposed to the air for a few days, when a thin pellicle will be formed on the surface of the water, containing millions of animalculæ.

To procure the eels in paste.- Boil a little flour and water till it becomes of a moderate consistence; expose it to the air in an open vessel, and beat it together from time to time, to prevent the surface from growing hard or mouldy: after a few days, especially in summer time, it will turn sour; then, if it be examined with attention, you will find myriads of eels on the surface. Apply them to

the microscope on a slip of flat glass, first putting on it a drop of water, taken up by the head of a pin, for them to swim in.

A very useful Method of breaking up Logs of Wood.

The usual way of breaking up logs of wood for the purposes of fuel, is by axes, and driving wedges in. This, particularly in roots of trees, is very laborious. It is also sometimes done by gunpowder, in the same way as stones and rocks are blasted; but this is very troublesome, as the plug is often driven out. A better method of performing this operation has lately been invented. A hole is bored with an augre, and a charge of powder introduced. An iron screw, with a good thread, having a hole bored through its axis, is then introduced into the hole, and turned till it come near to the powder. While the screw is putting in, a wire is kept in the hole through its axis, but it is afterwards drawn out, and a piece of twine dipped in a solution of nitre is put into its place. This quick match is set fire to, and by its slow burning, affords time for the operator to retire before it sets fire to the gunpowder.

By this means, any roots or old stumps of trees may be easily broken up.

A Process for purifying Fish Oil.

Take a gallon of crude stinking oil, and put to it a pint of water poured off from two ounces of lime slacked in the air; stir the mixture up several times for the first twenty-four hours; then let it stand a day, and the lime water will sink

below the oil, which must be carefully separated from it.

Another Method for purifying it more completely.

Take a gallon of crude stinking oil, and mix with it a quarter of an ounce of powdered chalk, a quarter of an ounce of lime slacked in the air, and half a pint of water; stir them together; and when they have stood some hours, add a pint of water, and two ounces of pearl-ashes, and place the mixture over a fire that will just keep it simmering, till the oil appears of a light amber colour, and has lost all smell, except a hot, greasy, soap-like scent. Then superadd half a pint of water, in which one ounce of salt has been dissolved, and having boiled it half an hour, pour the mixture into a proper vessel, and let it stand for some days, till the oil and water separate.

If this operation be repeated several times, diminishing each time the quantity of ingredients one-half, the oil may be brought to a very light colour, and rendered equally sweet with the common spermaceti oil.

Oil purified in this manner is found to burn much better, and to answer better the purposes of the woollen manufacture. If an oil be wanted thicker and more unctuous, this may be rendered so by the addition of tallow or fat.

FINE ARTS.

UNDER the name of Fine or Polite Arts, have been generally comprehended, painting, sculpture, architecture, poetry, and music: but in the common acceptation of words, the term fine arts is usually confined to the three first; and the professors of them are called, by way of eminence, artists.

It would exceed the limits to which we are confined in this work, to descant on the value and importance of the fine arts; and it is the less necessary, as this subject is beginning to be generally understood, since drawing has become a necessary branch of education.

To treat fully and professionally on the fine arts, would require a separate and extended work. What is here proposed, is to consider that part which enters into our system of usual school education.

Drawing strictly means the delineation of the contours or outlines of objects: and in this sense the term is used by painters, who distinguish between drawing and colouring: but the meaning of the word drawing is not sufficiently restricted, since, in common language, it has been applied to all such paintings as are executed with water colours on paper; the title of paintings having been rather given to those executed with oil colours on canvass.

Since this difference of the materials only afforded a very bad ground of distinction on which to found two species, the term paintings in water colours has very properly been lately introduced.