other; and by degrees considerable numbers are united, and blended together so as to form one complex feeling. This important power, or rather this law of the human mind, to the existence of which every day's experience bears testimony, is the foundation of memory, of recollection, of intellect, of affection and motive, of imagination and genius, of all the active powers and intellectaal energies of man, of habit, of character, of moral principle, of piety, virtue, and happiness. In what manner this law of nature operates, by what energy or medium ideas, in themselves distinct, are made to unite and blend with each other, is a mystery beyond the reach of human comprehension. It is like the attraction of cohesion in the natural world. It binds and cements all things, but its nature eludes all research.

During the state of vigilance the mental powers are in constant exercise. The senses, the memory, the recollection, the intellect, the imagination, the affections, the moral sense, all, in their turns, are

called forth to action. But in a few hours the machine is exhausted, its springs are relaxed, they require fresh winding up; and the state of sleep supervenes to refresh and to invigorate the wearied powers. The intellectual, and the active principles are for a time suspended. But how they cease to act; and how, after having been suspended, they resume their functions, is a fact which we cannot explain.

In passing from the state of vigilance to that of sound sleep, in which all the faculties are suspended, and the perception of duration is lost; and in the return from sleep to vigilance again, the mind finds itself in a state in which imagination alone seems to possess boundless sway, and reason, memory, and sometimes even the moral feelings themselves are suspended. Ideas are presented without any effort of the will, or any external impression. Scenes that have long been passed, and persons who have long been deceased, are revived, and a state of things the most preposterous is often set before the mind, in

which it acquiesces without reluctance, and which it admits without objection. What that state of the system may be which gives birth to these impressions, and which introduces this peculiar state of mind, is mysterious and inexplicable.

On the state and structure of the brain depend the developement, the exercise, and the actual state of the reasoning powers. Some imperceptible difference in the constitution of this delicate organ constitutes the main distinction between a philosopher and a brute-between a Newton and an idiot. Let some minute, indiscernible alteration occur in the internal structure, or in the vascular state of this delicate substance, and the man of talent becomes a raving lunatic-the philosopher who astonished the world by the magnitude and variety of his discoveries, is transformed into a child; and the man, the extent of whose genius, or the point and delicacy of whose wit were the delight and wonder of all who conversed with him, sinks into a dotard and a driveller. Such

is the infirmity of human nature. Upon such a slender thread do the most splendid talents depend. Such is the narrow, the mysterious, the incomprehensible limit which separates between the wise man and the fool.

The whole man is continually changing. The body passes from infancy to childhood, from childhood to youth, from youth to manhood, from manhood to declining life, and from decline to decrepitude, and some, who are most competent to judge, have computed that every particle of the corporeal system is changed repeatedly in the course of three-score years and ten.

And as far as we can judge, the sentient principle, what we call the mind, is equally mutable with the body. All that we know of mind is a system of ideas, of recollections, of intellectual and moral feelings and habits. We can comprehend no more of the essence of mind than we do of matter. But there is no greater difference between the body of an infant, and the various forms which the body assumes in its passage to

decrepitude, than there is between the system of ideas and feelings of the child, and those of youth, of manhood, and of declining years. If, then, the body changes in every part in its passage through a lengthened life, we have the same reason to conclude that the mind undergoes a similar and equal change, and yet the conscious SELF remains unchanged. The same in youth as in infancy, in manhood as in youth, in decrepitude as in vigorous manbood. In the entire change of body and mind, if such change actually takes place, as in the immutable identity of both. In what does this personal identity consist? What is it that constitutes the conscious self through all the vicissitudes of human existence? Of the fact we are assured; but of the mode we are utterly ignorant.

Finally, man dieth and wasteth away: Man giveth up the ghost, and where is he? After the lapse of years, at the destined period, fixed in the immutable counsels of heaven, the principle of life withdraws, and with it the power of perception, of me