Thus a German, of the name of Spalding, of high attainments, informs us, that after great mental labour, he was intending to write this receipt: “fifty dollars, being one half-year’s rate,” but quite unconsciously concluded it thus: “fifty dollars through the salvation of Bra.” And the author of the “Spiritual Treasury,” Mason, during his devotion to its composition, had, as he believed, taken the address of a visitor on whom he was to wait; but on referring to his note, he read, not the address, but—“Acts ii. verse 8.” Children have _naturally_ a want of power of concentration. I have told you that if a new or more attractive object strikes their sight, they will drop that which they were holding; and Foote would often, while taking a pinch, let his snuff-box fall from his hand, if for a moment his attention was diverted. ASTR. The reverse of wandering, then, you term _concentrativeness_. You would not stigmatize the passive or involuntary form of abstraction, as the reverie of a _monomaniac_. EV. No. As attention is concentration of a sense, abstraction is the concentration or attention of the mind; therefore the power of fixing the senses and forgetting the mind, is attention, that of fixing the mind and forgetting the senses, is abstraction—philosophy, if you will. The active form, the power of fixing the attention on one subject, or of separating ideas and bringing them into association on one point, is the great characteristic of the philosopher and the mathematician. That inattention to _minutiæ_ during this abstraction, has, I grant, caused the shafts of satire to be profusely flung at many a “learned pundit;” for the jokes of Rabelais are eclipsed by the eccentricities of our sages: Dominie Sampson is no caricature. As I trace these forms of reverie from monomania to its curious contrast, the _folie raisonnante_ of men of one idea, (in which there is an aberration of intellect, or want of consciousness on _all subjects but one_,) and so on to philosophical abstraction, we shall learn, not without some humility, how close an alliance does really exist between great wits and madness. The records of history and fiction teem with the illusions of the monomaniacs from intense impression. The madness of Ophelia and of Lear, are true and faithful illustrations of the effects of _brooding over sorrow_. In the monarch, indeed, that one momentary glimpse of reason when the word “_king_” like an electric shock falls on his ear, and, for an instant, lights up his intellect, which as suddenly darkness again overshadows, beautifully shows forth by contrast this madness of one idea. Dr. Gooch relates the case of a lady, who in consequence of an alarm of fire, believed that she was the Virgin Mary, and that her head was constantly encircled by a brilliant halo or glory. A gentleman, on narrowly escaping from the earthquake at Lisbon, fell into a state of delirium whenever the word “earthquake” was pronounced in his hearing.