III. HOW WE SHOULD LIVE.
So should we live, that every hour
May die as dies the natural flower,
A self-revolving thing of power.
That every thought and every deed
May hold within itself the seed
Of future good and future need:
Esteeming sorrow, whose employ
Is to develop, not destroy,
Far better than a barren joy.

IV. TO MY SON.

My son, be this thy simple plan:
Serve God, and love thy brother man;
Forget not, in temptation's hour,
That sin lends sorrow double power;
Count life a stage upon thy way,

And follow Conscience, come what may;
Alike with earth and heaven sincere,
With hand, and brow, and bosom clear,
"Fear God, and know no other fear."

LESSON IV. THE STREAM OF LIFE.

1. LIFE bears us on like the stream of a mighty river. Our boat at first glides down the narrow channel, through the playful murmuring of the little brook and the winding of its grassy border. The trees shed their blossoms over our young heads, the flowers on the brink seem to offer themselves to our young hands; we are happy in hope, and we grasp eagerly at the beauties around us; but the stream hurries on, and still our hands are empty.

2. Our course in youth and manhood is along a wider and deeper flood, amid objects more striking and magnificent. We are animated by the moving picture of enjoyment and industry passing before us; we are excited by some shortlived disappointment. The stream bears us on, and our joys and our griefs are alike left behind us.

3. We may be shipwrecked, but we can not be delayed; whether rough or smooth, the river hastens toward its home, till the roar of the ocean is in our ears, and the tossing of its waves is beneath our feet, and the land lessens from our eyes, and the floods are lifted up around us, and we take our leave of earth and its inhabitants, until of our farther voyage there is no witness save the Infinite and Eternal.-HEBER.

PART IX.

FIRST DIVISION OF CHEMISTRY.

[This subject is continued in the Sixth Reader.]

LESSON I.-INTRODUCTORY VIEW.

1. THERE are three great divisions of the science of nature, and these are embraced in the departments of Natural History, Natural Philosophy, and Chemistry. Under the first are included zoology, botany, and geology, whose province it is to describe and classify all material things, both animate and inanimate. Natural Philosophy, taking natural objects as thus classified, treats of their general and permanent properties, of the laws which govern them, and the reciprocal action which, without change of form or character, and generally at appreciable distances, they are capable of exerting upon each other.

2. Chemistry advances farther in her investigations, and with scrutinizing minuteness leads us far into the hidden mysteries of nature. It treats of the intimate action of substances upon each other, such as chemical mixtures or combinations, which always result in changes of form and character. It presents to us, as a first lesson, the astonishing fact that, notwithstanding the countless variety of forms and properties of matter which nature presents to us as things essentially different, only about sixty elementary substances are known to exist, and that it is merely by their different combinations that they are made to present to our senses these infinite diversities.

3. Proceeding a little farther, our wonder increases on learning that nearly all the objects with which we are acquainted are, to use a common phrase, "made up" almost exclusively of at least not more than four of these elementary substances, and that these are the three gases, oxygen, hydrogen, and nitrogen, together with carbon. Indeed, charcoal and the diamond, though totally unlike each other, are composed of carbon alone. Water is formed of oxygen and hydrogen; the air we breathe, and the corrosive nitric acid, are alike composed of oxygen and nitrogen; vegetable substances, infinite in diversity of form and properties, are formed almost wholly of oxygen, hydrogen, and carbon; and ani

mal substances are formed chiefly of these three elements. with the addition of nitrogen. So largely does oxygen enter into combinations with other elementary substances, that one half of the entire globe itself is said to be formed of this gas, or, as one writer has expressed it, "of compressed and hardened air."

4. How one substance can assume forms and properties so different as charcoal and the diamond, or how two or more substances, merely by different combinations of them, can produce things so totally unlike as common air and nitric acid, or as sugar and vinegar, we are unable to conceive; but chemistry teaches us the facts, and leaves us to ponder over such mysteries in wonder and admiration. But it is not merely a science that is full of wonders; in its various departments it is intimately related to all the other natural sciences, and it forms the basis of all the useful arts. Thus, what is termed Inorganic Chemistry treats of the laws of combination by which are formed all those compound bodies which are not the products of organized life. There is not a single manufacture or art, from the smelting of ore and the making of bread, to the manufacture of gunpowder and electric telegraphing, that is not more or less dependent upon this branch of chemistry.

5. In what is called Organic Chemistry we trace the combinations of the same elementary substances, and chiefly the three gases and carbon, as modified by the principle of life; and thus animal and vegetable chemistry are recognized as branches of one greater science. In Agricultural Chemistry we study the applications of chemistry to agriculture; and being made acquainted with the chemical ingredients of plants and soils, we are enabled so to avail ourselves of the laws of vegetable growth as to adapt our soils to the nature of the product required. Indeed, so extensive are the applications of chemical principles, that they enter, in some mode or form, into every branch of industry, and every department of civilized life.

LESSON II.-FIRST PRINCIPLES: ULTIMATE ATOMS.

1. WHEN a stick of wood is burned for fuel, it is destroyed as a stick of wood, but not one of the particles, or, more properly, atoms, which composed it, has been annihilated. In the ashes of the wood, and in the atmosphere in which it was

consumed, every atom must still exist. Some of these atoms may glisten in the morning dew, crystallize in the snow-flake, or fall to the waiting fields in the grateful rain. Other atoms of the stick of wood apparently destroyed may appear the next year in some stick of sugar-candy, and again, ages hence, may constitute a little but important part of some votive monument of marble. Such changes are not only possible, but probable.

2.

5.

When by the wind the tree is shaken,
There's not a bough or leaf can fall,
But of its falling heed is taken

By One that sees and governs all.
The tree may fall and be forgotten,
And buried in the earth remain;
Yet from its juices rank and rotten
Springs vegetating life again.
The world is with creation teeming,
And nothing ever wholly dies;
And things that are destroyed in seeming,
In other shapes and forms arise.

And Nature still unfolds the tissue

of unseen works by spirit wrought;

And not a work but hath its issue

With blessing or with evil fraught.-KENNEDY.

6. The journey of an atom in its ceaseless round would be even more wonderful than the adventures of a drop of water -now in the ocean, next in the rainbow, then a part of an iceberg, and again on its way to the purple cloud. The ocean has been in the clouds-perhaps many times; and yet, in all its changes, not a particle has been lost.

7.

"Nothing is lost: the drop of dew

Which trembles on the leaf or flower,

Is but exhaled to fall anew

In summer's thunder-shower;

Perchance to shine within the bow

That fronts the sun at fall of day,
Perchance to sparkle in the flow
Of fountains far away."

8. The plant is made of the mineral, and the animal consumes the plant and returns to the earth, again to enter into new combinations. Shakspeare says,

"Imperious Cæsar, dead, and turn'd to clay,
Might stop a hole, to keep the wind away;

Oh that the earth, which kept the world in awe,
Should patch a wall to expel the winter's flaw!"

9. Another has expressed the same truth in the following words: "Man, moving to-day the monarch of a mighty people, in a few years passes back to his primitive clod, and that combination of elementary atoms which is dignified with the circle of sovereignty and the robe of purple, after a period may be sought for in the herbage of the fields and in the humble flowers of the valley."-HUNT.

10. We live in a world of change. The growth and composition of organic matter, the rusting of metals, the crumbling of rocks, and the combustion of fuel, afford innumerable illustrations of this truth. Nothing is at rest-nothing is permanent; and yet, in all the changes which matter has undergone, from creation's dawn to the present time, we have no reason for believing that the minutest atom has been destroyed. Let not man, then, contemn the atom which he could not create, and which he has not the power to destroy.

LESSON III.-THE MAN AND THE ATOM.

1. "SMALL atom, unconsidered,
Unfelt, and scarcely seen!

Thou hast no worth upon the earth-
So infinitely mean.

2. "Useless thou art, oh atom'!

And, absolute in might',

If I decree thou shalt not be',
I can destroy thee quite."
3. "Ah! no; thy hand is powerless.
I hold a life too high;

A strength innate, as old as fate;
I change, but can not die.

4. "Destruction can not touch me;
The hand alone which wrought
My shape and thine-a hand divine-
Can hurl me into naught.

5. "Thou mayst on waters cast me,
Or loose me to the wind,
Or burn in fire, at thy desire,
So that thou canst not find;

6. "But I shall hold existence
To earth's remotest time,
And fill in space my destined place,
Though humble, yet sublime.

7. "Ere yet offending Adam

8.

Fell from his pure estate,

Or tended flowers in Eden's bowers,
With Eve, his happy mate';

"I, even I, existed,

And played my proper part
In God's great plan-oh, little man,
Reflect on what thou art!

9. "Couldst thou destroy my being',
Thy hand might reach the spheres',
And bid the sun no longer run

His course among his peers.