There are extraordinary cases. A man may have so thoroughly prepared himself by long meditation and study, he may have his mind so charged with an abundance of thought, that it may employ him for ten or twelve hours consecutively, merely to put down or to unravel the conceptions already matured in his soul. It was in some such way, that Dryden, we are told, occupied a whole night, and to a late hour in the next morning, in penning his Alexander's Feast. But these are the exceptions. In most instances two or three hours are as much as an author can spend at a time in delivering the first fruits of his field, his choicest thoughts, before his intellect becomes in some degree clouded, and his vital spirits abate of their elasticity. Nor is this all. He might go on perhaps for some time longer with a reasonable degree of clearness. But the fertility which ought to be his boast, is exhausted. He no longer sports in the meadows of thought, or revels in the exuberance of imagination, but becomes barren and unsatisfactory. Repose is necessary, and that the soil should be refreshed with the dews of another evening, the sleep of a night, and the freshness and revivifying influence of another morning. These observations lead, by a natural transition, to the question of the true estimate and value of human life, considered as the means of the operations of intellect. A primary enquiry under this head is as to the duration of life: Is it long, or short? The instant this question is proposed, I hear myself replied to from all quarters: What is there so well known as the brevity of human life? "Life is but a span." It is "as a tale that is told." "Man cometh forth like a flower, and is cut down: he fleeth also as a shadow, and continueth not." We are "as a sleep; or as grass: in the morning it flourisheth, and groweth up; in the evening it is cut down, and withereth." The foundation of this sentiment is obvious. Men do not live for ever. The longest duration of human existence has an end: and whatever it is of which that may be affirmed, may in some sense be pronounced to be short. The estimation of our existence depends upon the point of view from which we behold it. Hope is one of our greatest enjoyments. Possession is something. But the past is as nothing. Remorse may give it a certain solidity; the recollection of a life spent in acts of virtue may be refreshing. But fruition, and honours, and fame, and even pain, and privations, and torment, when they ere departed, are but like a feather; we regard them as of no account. Taken in this sense, Dryden's celebrated verses are but a maniac's rant: To-morrow, do thy worst, for I have lived to-day: Be fair, or foul, or rain, or shine, The joys I have possessed, in spite of fate are mine. Not heaven itself upon the past has power, But what has been has been, and I have had my hour.