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ject, are thrown, with a design of getting the clearest possible knowledge of it, ourselves, and of communicating it most eftirtually to others./

Q. To whom i gi most useful:

A. It is useful ti all men; panicularly, to those who have to teach or reason with others: as Dieachers, lawyers, legislators, &«. The art of logic is nothing more than the natural systems of reasoning methodised. All who think and judge for themselves, though many are unconscious of it, constantly use logic.

ETHICS.

Q. What are ethics?

A. The doctrine of manners, or the science of morals in the behaviour and conduct of man, either in public or private life.

Q. What is the object of this science?

A. The exercise of right reason in all the circumstances of our actions, affairs, and relations, in life; so that we may arrive at the highest degree of moral perfection and beatitude.

PHYSICS.

Q. What are physics?

A. The doctrine of natural bodies, their phenomena, causes, and effects; with their various affec

tions, motions, and operations. Physics are also called physiology, and natural philosophy.

Q. In what, does this science instruct us?

A. It teaches us to explain all the phenomena of the earth: as, the atmosphere, meteors, earthquakes, tides, &c.

Familiarly, we say, that nature employs four elements--earth, water, air, and fire: but, philosophically, the elements, or radicals, amount to nearly fifty; as all those, except fire, the caloric of the modern chemists, are compounded bodies.

OF THE ATMOSPHERE.

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Q. What is the atmosphere?

A. A transparent, invisible, elastic fluid, encompassing the earth, and moving along with it in its apnual and diurnal motions.*

Pure atmospheric air is composed of three gageous substances, only-oxygen, nitrogen, and carbonic acid gas; in the proportion of 22 parts of oxygen, 77 of nitrogen, and 1 part in a 100 of the last. But the air that we breathe, is perpetually contaminated by a variety of exhalations from the earth.

* Mr. Boyle found by experiment, that air, by its elasticity, would so expand itself as to occupy 13,769 times more space than contained it before. And we know that air may be compressed to 128th part of the space it naturally occupius. Its expansion and compressibility, may, howerer, be considered as infinite.

Oxygen is the principle of combustion, and the vehicle of heat; and is absolutely necessary for the support of animal life.

Nitrogen is chiefly distinguished by its being incapable of supporting combustion, or animal life. It has the effect of neutralizing, in some measure, the properties of oxygen; thus, rendering it fit for breathing and promoting combustion: and is highly favourable to vegetation.

Carbonic acid gas is formed by the respiration of animals, and by combustion. It is the proper nutriment of vegetables; which nature has endowed with organs for its decomposition.*

Q. Of what gravity, is the atmosphere, and what are its principal effects.

A. A quart of atmospheric air, at the earth's surface, weighs 16 grains; being 914 times lighter than rain water: but, from its great height, it presses upon the earth, and all the bodies thereon, so powerfully, as to bind them down with a force amounting to upwards of 15 pounds weight upon every square inch: hence, it prevents the vessels of ani. mals and plants from being too much distended by the impetus of the circulating blood and juices.

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* One gallon of common air is sufficient for a man during the space of one minute, and no longer: a lighted can. dle, also, destroys the vivifying quality of a gallon of air in one minute, and without a fresh supply, it will cease to burn.

Q. Is the atmosphere of the same density and heat, at all distances from the earth?

A. No: the air is lighter, in geometrical proportion, the higher we ascend: and its heat also de. creases; but not in a similar ratio.

By that lessening in gravity, the altitude of mountains is known; from the falling of the mercury in the barometer,

OF METEORS.

Q. What is a meteor?

A. A transient body, or the resemblance of a body, formed in the atmosphere, and exhibiting various appearances.

Q. How are meteors divided?

A. Into three kinds: the igneous, aerial, and aqueous. Of the igneous kind, are, lightning, aurora borealis, ignis fatuus, and other fiery pheno

The aerial, consists of winds. The aqueous, are composed of vapours, or watery particles, variously separated, and condensed, by cold: such are, clouds, bail, and snow; rain, waterspouts, dew, and the like,

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ELECTRICITY.

Q. What is Electricity?

A. Electeicity, or electrical matter, is a subtle fire which pervades all nature, and produces most singular and extraordinary phenomena.

It is the cause of thunder and lightning, the aurora borealis, and, in many instances, of earthquakes.

The science of electricity is the art of moving, and accumulating, this astonishing agent; so as to exhibit its various effects.

Q. How does it appear that thunder and lightning are the effects of electricity?

A. Dr. Franklin has proved, by a variety of esperiments, that the lightning of electricity, and that wliich flashes in the clouds during a thunder storm, are of exactly the same kind, and operate in the the same manner.

OF LIGHTNING AND THUNDER.

Q. What is Lightning?

A. A large, bright flame, darting swiftly through the air; of momentary duration, and commonly attended with thunder.

Q. How is this meteor accounted for?

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