within bounds. Some idea, some fancy, takes possession of the brain; and however ridiculous, however distressing, however ruinous, haunts us by a sort of fascination through life.
Not only is this principle of excessive irritability to be seen at work in our more turbulent passions and pursuits, but even in the formal study of arts and sciences, the same thing takes place, and undermines the repose and happiness of life. The eagerness of pursuit overcomes the satisfaction to result from the accomplishment. The mind is overstrained to attain its purpose; and when it is attained, the ease and alacrity necessary to enjoy it are gone. The irritation of action does not cease and go down with the occasion for it; but we are first uneasy to get to the end of our work, and then uneasy for want of something to do. The ferment of the brain does not of itself subside into pleasure and soft repose. Hence the disposition to strong stimuli observable in persons of much intellectual exertion to allay and carry off the over-excitement. The improvisatori poets (it is recorded by Spence in his Anecdotes of Pope) cannot sleep after an evening's continued display of their singular and difficult art. The rhymes keep running in their head in spite of themselves, and will not let them rest. Mechanics and la-
