of duration appears long to us when the succession of ideas in our mind is quick, and short, when the succession is slow; but he does not assert that this law is subject to no exceptions.

From the extreme thinness and subtilty of the subject, it is very difficult to ascertain any general laws that serve to regulate the action of the human mind, and to the operation of which all the phenomena may be referred. Exceptions to these rules must be expected to recur; but these, instead of vacating or annulling the law, only serve to confirm its existence. My daily experience convinces me of the truth of the general maxim prescribed on the subject of our perceptions of succession and duration; that the more rapid the succession of ideas, the longer does time appear, and the more slow, that succession the shorter. If I spend the morning in my study engaged in close attention of the mind, to some interesting subject, I am scarcely sensible of the progress of time, insomuch that I am often surprised to find the hour of dinner arrived; but if the same time be devoted to making or returning visits in the city, the change of scene, and the variety of ideas excited by meeting with different characters, and entering into various and desultory conversations, makes the morning assume its natural dimensions. If I set off upon a journey, the diversity of objects presented to my view, and the rapid train of ideas, which are awakened by riding through a cultivated country, and having picturesque scenery displayed to my view, make time seem to rest upon his wing, and I in one day, appear to have gone through the lapse of several. I take it, therefore, that the general maxim of Mr. Locke, if properly interpreted, is irrefragably true; that, cæteris paribus, the more rapid the succession of our ideas, the slower appears the progress of time, and vice versa. I say cæteris paribus, because it implies that the mind be in the same state or condition as to tranquillity or disturbance, happiness or misery, indifference or strong desire, pain or

pleasure, at each time in which the experiment is made. When we are under the influence of any strong passion, or disquieted by extreme pain, then this general law of our nature is contravened by the opposing or preponderating influence of another part of our moral constitution. It is not, therefore, true, as asserted by Dr. Reid, that upon Mr. Locke's principles, when a man is impatient under any pain or distress, or eager in the expectation of some happiness, the succession of his ideas is very quick, since time appears long to him; and on the other hand, when he is pleased, and happy in agreeable conversation, or delighted with a variety of agreeable objects that strike his senses or imagination, the succession of ideas should be slow, since time flies away, the reverse of which in both cases he supposes, and justly, to take place. Mr. Locke's principles lead to no such conclusions. He merely propounds a law of our moral constitution, from which cases of this kind exhibit exceptions, present contradictory phenomena, and for the solution of which we must have recourse to some other constituent principle of our nature. A Newton fixing his attention closely in the solution of a philosophical question, is insensible of the lapse of time, the metaphysician would say, because the succession of his ideas would be slow, and he would find pleasure in the occupation. Let the same Newton be racked with illness, and his mind now turned from scientifical pursuits, is wholly engrossed with his pain; his time now passes sluggishly away, not because the succession of his ideas is more rapid than before, for in this case also it would be slow; but because a new circumstance intervenes, that changes the nature of the case, the pain is irksome, and the time in which it is endured must appear long, although in a different state of mind it might pass rapidly away. The phenomena exhibited by the human mind, in its perceptions of the progress of time are endless, and sometimes inexplicable; because not susceptible of being reduced to any general laws

of our constitution. "I have heard a military officer," says Dr. Reid, "a man of candour and observation, say, that the time he was engaged in hot action, always appeared to him much shorter than it really was. Yet, I think, it cannot be supposed that the succession of ideas was then slower than usual." There is no necessity for supposing that the succession of ideas was slower than usual on such an occasion, or for resorting to a theory discrepant from that of Mr. Locke, in order to explain the phenomenon.

Several considerations may be offered, which serve to account in a satisfactory manner for the fact, that to an officer under such circumstances time might appear short.

In the first place, the active employment of his mind, and almost total absorption of all its powers, in the great object of his pursuit, viz. to obtain the victory, and in order to this purpose, the watching of the movements of the enemy, and directing those of his own army, would to a man naturally brave and accustomed to danger, have a tendency to accelerate to him the progress of time. Deep and solicitous occupation, in any business which we are extremely anxious to perform, makes us loose all sense of the lapse of time.

In the next place, while it is not denied, that during the heat of action, and the rapid movements of two contending armies, our ideas would succeed each other with great rapidity; yet it is to be observed also, that, except with a few of them which were the most interesting, the very rapidity of their succession would prevent them from producing the usual effect upon the mind, by occasioning it, from a distinct notice taken of each of them, to mark the progress of time, As bodies may pass within our sphere of vision, with such immense velocity as to be imperceptible to the eye, so when the mind is excited by the heat and noise of battle, many of the ideas which shoot through the fancy in such quick succession, would be utterly unnoticed. We know that lightning consists of a small portion of electric fluid, passing from the

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cloud, and that like all other bodies, it travels by distinct and successive stages from the cloud to the earth. Why then, does it appear to us to be but one continuous stream of fire, reaching from the cloud to the earth. Evidently, because its velocity is so great, that our perceptions are not quick enough to mark the several stages of its progress. Beings of quicker perceptions may do this, for ought we know, and behold it in its descent, like a ball of fire moving through space, in the same manner as we might view the motion of a red-hot cannon ball, passing slowly through the hemisphere." If a burning coal, be nimbly moved round in a circle," says Newton, " with gyrations continually repeated, the whole circle will appear like fire; the reason of which is, that the sensation of the coal in the several places of that circle, remains impressed on the sensorium, until the coal return again to the same place. And so in quick consecution of colours, viz. red, yellow, green, blue and purple, the impression of every colour remains on the sensorium, until a revolution of all the colours be completed, and that first colour returns again. The impressions, therefore, of all the suc cessive colours are at once in the sensorium, and beget a sensation of white."* These facts assist us in furnishing a solution of the problem relative to the officer before mentioned, as they go to show, that many of the objects which passed in rapid review before his senses, during the heat of contest, would not convey distinct notices to the mind, and of course would pass by unheeded, and that the succession of our ideas may be so very rapid as to run into each other, and thus present only a single perception to the mind. A commander thus circumstanced would after all, have his whole attention engrossed by a very few ideas, whose succession alone would be distinctly marked by him. These considerations, it is presumed, are sufficient to explain the

Newton's Optics.

fact, that time might appear short to him during the heat of action. But suppose as a spectator of the same scene, a friend, wife or child, deeply interested for his fate, looking intently upon it; and could we imagine a period, in which time would advance with a more lingering pace, than while he saw him in the rage of battle, and every moment in danger of death? In this case, deeply interested as he would be, yet he would not be thrown into such a tumult of emotions and confused mixture of sensations, as not to be able leisurely to mark the succession of his thoughts, and at the same time would be wrought up to the highest pitch of anxiety. Every minute in that condition might appear an hour.

Let, then, a fair construction be given to the maxim of Mr. Locke, and it will be found to have its foundation in a just philosophy, and in correct and comprehensive views of the structure and operations of the human mind.

Since writing what is contained above, in conversation with an intelligent military officer of our country, I have been furnished with some facts, that completely establish the theory which is maintained. He remarked, that, in the different engagements in which he was concerned, his perception of the progress of time, varied according to circumstances. In general, he said, when his mind was occupied merely with the management of his own men, and watching the movements of the enemy, time appeared shorter than usual: insomuch, that on one occasion, when the opposing force gave way sooner than was anticipated, both he and his soldiers expressed their surprise at their speedy flight; but were no less astonished to find, upon computing the time, that the greater part of an hour had passed in the action. On another occasion, however, he said, when he was contending with a superior force, and in danger of being overpowered by them, being every moment in expectation of a reinforcement, time appeared very tedious and long,