They who possess this amusing instrument, may easily per form with it a variety of pleasing experiments; among others, the following: - Leave some vinegar exposed in a saucer, for a few days, to the open air; then place a drop of it, by means of a clean pen, or a camel's hair brush, on the transparent object-plate of the microscope; and if the object-plate be properly illuminated from below, you will observe in this drop of liquor animals resembling some small eels, which are in continual motion.

If you slightly bruise some pepper-corns, and infuse them in water for a few days, and then expose a drop of it to the microscope, a number of animals of a different kind will be visible. These are of an oblong shape, and, like the others, in continual motion, going backwards and forwards in all directions, turning aside when they meet each other, or when their passage is stopped by some obstacle.

In other infusions, as in that of new hay, differently shaped animalcules will be found. When the drop in which they swim, and which to them is like a pond, becomes diminished by evaporation, they gradually retire towards the middle.

where they accumulate, and at length perish when entirely deprived of moisture. Previously to this, they appear in great distress, writhe their bodies, and endeavour to escape from that state of uneasiness which they evidently feel.

If the smallest quantity or drop of sulphuric acid be put into a drop of the infusion which swarms with these insects, they immediately throw themselves on their backs, and expire; sometimes losing their skin, which bursts, and suffers small particles of air to escape.

Those who wish to be furnished with microscopic eels, at all seasons, may have them in common paste, such as the bookbinders commonly use. It should neither be too stiff, nor too watery. Expose it to the air, and prevent its harden-ing or becoming mouldy on the surface, by beating it well together, when it has that tendency. After some days it will become sour; and then, if examined attentively by a micro-scope, multitudes of exceedingly small, long, and slender animalcules will be visible; these will grow larger, till they are of sufficient size to be seen by the naked eye. A drop or two of vinegar should now and then be poured on the paste; and sometimes, to prevent its being dry, a little vinegar and water. By this means microscopic eels may be had all the year. They must be applied to the microscope upon any flat surface, after having first put on it a very small drop of water for them to swim in. These are very entertaining objects when examined by any kind of microscope, but particularly the solar one, by which the motions of their intestines may very plainly be distinguished; and when the water is nearly dried away, and they are on the point of expiring, their mouths may be seen opening to a considerable width.

If some of the dust of the puff-ball be examined with the microscope, it appears to consist of perfectly round globules, of an orange colour, the diameter of which is only about the one-fiftieth part of the thickness of a hair, so that each of this grain is but the 1/12500 part of a globule, equal in diameter to the breadth of a hair.

The farina of flowers is found to be regularly or uniformly organized in each kind of plant. In the mallow, for example, each grain is an opaque ball, covered over with small points. The farina of the tulip, and of most of the liliaceous kind of flowers, bears a striking resemblance to the seeds of the cucumber: that of the poppy is like grains of barley.

There are certain plants, the leaves of which seem to be pierced with a\multitude of small holes. Of this kind is the St. John's Wort. If a fragment of this be viewed with a good microscope, the supposed holes are found to be vesicles, contained in the thickness of the leaf, and covered with an exceedingly thin membrane; and these are thought to be the receptacles which contain the essential and aromatic oil peculiar to the plant. The view exhibited by those plants which have down, such as borage, nettles, etc. is exceedingly curious. When examined by a microscope, they appear to be covered with spikes. Those of borage are, for the most part, bent so as to form an elbow; and though really so close, they appeal by the microscope, to be at a considerable distance from each other. The entire appearance is very similar to that of the skin of a porcupine.

There are two kinds of sand, viz. the calcareous and the vitreous: the former, examined with a microscope, resembles large irregular fragments of rock; but the latter appears like so many rough diamonds. In some instances, the particles of sand seem to be highly polished and brilliant, like an assemblage of diamonds, rubies, and emeralds.

Charcoal is a fine object for the microscope: it is found to be full of pores, regularly arranged, and passing through its whole length.

Those who wish to observe the circulation of the blood, by means of the microscope, may readily obtain the desired satisfaction. An object employed chiefly for this purpose is the delicate transparent membrane which unites the toes of the frog; another object is the tail of the tadpole. If this membrane be extended, and fixed on a piece of glass illuminated below, the motion of the blood in the vessels will be distinctly visible; the appearance resembles a number of small islands, with a rapid current flowing between them.

Take a small tadpole, and, having wrapped its body in a piece of moist cloth, place its tail on the object-plate of the microscope, and enlighten it below, and you will see very distinctly the circulation of the blood; which in some of the vessels proceeds by a kind of undulation, and in others with a uniform motion. The former are thought to be the arteries in which the blood moves, in consequence of the alternate pulsation of the heart; the latter are said to be the veins. The circulation of the blood may be seen also in the legs and tails of shrimps. The transparent legs of small spiders, and those of bugs, will also afford the means of observing the circulation of the blood to very great advantage. The latter are said, by Mr. Baker, to exhibit an extraordinary vibration of the vessels, which he never saw any where else. Very small fish are good objects for this purpose; but the most curious of all spectacles of this kind, is that exhibited by the mosentery of a living frog, applied in particular to the solar microscope.

If you take off a small piece of the epidermis, or scarf skin, of the hand, by means of a sharp razor, and place it on the object-plate of the microscope, you will see it covered with a multitude of small scales, so exceedingly minute, that, accord ing to Leuwenhoek, a grain of sand would cover two hundred of them. These scales are arranged like those on the back of fishes, like the tiles of a house, each in part covering the other. To ascertain the form of these little scales, scrape the skin with a penknife, and put this dust into a drop of water, and it will be seen that these scales, small as they are, have, in general, five planes, and that each consists of several strata. Underneath these scales are the pores of the epidermis, which, when the former are removed, may be distinctly seen, apparently like small holes, pierced with an exceedingly fine needle. In the length of an inch, twelve hundred have been counted, so that, in a surface equal to a square inch, there are fourteen thousand; and as there are one hundred and forty-four inches in a square foot, the number of pores in a square foot of surface would be more than two millions; and as the surface of the human body is reckoned at fourteen feet, the number of pores in its surface, through which there is a perpetual perspiration going on, must be more than twenty-eight millions.

The hairs of animals, seen through a microscope, appear to be organized bodies: they are composed of long, slender, hollow tubes; some seem to be composed of several small hairs, covered with a common bark; others are hollow throughout. The bristles of a cat's whisker, when cut transversely, exhibit the appearance of a medullary part, which occupies the middle, like the pith in the twig of the elder-tree. A human hair, cut in the same manner, shows a variety of vessels in very regular figures. Hair taken from the head, the eyebrows, the nostrils, the beard, the hand, etc. appear unlike, as well in the roots as in the hairs themselves, and vary as plants do of the same genus, but of different species. Those of the hedgehog contain a kind of real marrow, which is whitish, and formed of radii meeting in a centre. A split hair appears like a stick shivered with beating.'

Nothing can be more curious than the appearance exhibited by mouldiness, when viewed through a microscope. If looked at by the naked eye, it seems nothing but an irregular tissue of filaments; but the magnifying-glass shows it to be a forest of small plants, which derive their nourishment from the moist substance which serves them as a base. The stems of these plants may be plainly distinguished, and sometimes ther buds, some shut, and some open. They have much similarity to mushrooms, the tops of which, when they come to maturity, emit an exceedingly fine dust, which is their seed.

Upon examining the edge of a very keen razor with a microscope, it will appear as broad as the back of a thick knife, rough, uneven, full of notches and furrows. An exceedingly small need e resembles a rough iron bar. But the sting of a bee, seen through the same instrument, exhibits every where a polish exceedingly beautiful, without the least flaw, blemish, or inequality, and ends in a point too .fine to be discerned.

A small piece of exceedingly fine lawn, appears, through a microscope, like a hurdle or lattice, and the threads themselves seem coarser than the yarn with which ropes are made for anchors. But a silkworm's web appears perfectly smooth and shining, and every where equal.

The smallest dot that can be made with a pen, appears, when viewed by the microscope, an irregular spot, rough, jagged, and uneven. But the little specks on the wings or bodies of insects, are found to be most accurately circular.

A microscope will prove the most boasted performances of art to be ill-shaped, rugged, and uneven. The finest miniature paintings appear before this instrument as mere daubings, plastered on with a trowel, entirely void of beauty, either in the drawing or the colouring;. The most even and beautiful varnishes and polishings will be found to be mere roughness, full of gaps and flaws. Thus sink the works of art, before the microscopic eye. But the nearer we examine the works of God, even in the least of his productions, the more sensible shall we be of his wisdom and power. Apply the microscope to any, the most minute of his works, nothing is to be found but beauty and perfection. If we examine the numberless species of insects that swim, creep, or fly around us, what proportion, exactness, uniformity, and symmetry, shall we perceive in all their organs! what a profusion of colouring! azure, green, and vermilion, gold, silver, pearls, rubies, and diamonds; fringe and embroidery on their bodies, wings, heads, and every other part! how high the finishing, how inimitable the polish, we every where behold!

Their wings, all glorious to behold!

Bedeck'd with azure, jet, and gold,

Wide they display: the spangled dew

Reflects their eyes and various hue. Gay.

The most perfect works of art betray a meanness, a poverty, an inability in the workman; but the works of nature plainly prove, that "the hand which formed them was divine."