already knows; so that by the natural tendency to imitate, he may get into the habit of repeating them one after another.  Gradually as there occur cases in which he omits to name one or more of the properties he has become acquainted with, she introduces the practice of asking him whether there is not something more that he can tell her about the thing he has got.  Probably he does not understand.  After letting him puzzle awhile she tells him; perhaps laughing at him a little for his failure.  A few recurrences of this and he perceives what is to be done.  When next she says she knows something more about the object than he has told her, his pride is roused; he looks at it intently; he thinks over all that he has heard; and the problem being easy, presently finds it out.  He is full of glee at his success, and she sympathises with him.  In common with every child, he delights in the discovery of his powers.  He wishes for more victories, and goes in quest of more things about which to tell her.  As his faculties unfold she adds quality after quality to his list:  progressing from hardness and softness to roughness and smoothness, from colour to polish, from simple bodies to composite ones—­thus constantly complicating the problem as he gains competence, constantly taxing his attention and memory to a greater extent, constantly maintaining his interest by supplying him with new impressions such as his mind can assimilate, and constantly gratifying him by conquests over such small difficulties as he can master.  In doing this she is manifestly but following out that spontaneous process which was going on during a still earlier period—­simply aiding self-evolution; and is aiding it in the mode suggested by the boy’s instinctive behaviour to her.  Manifestly, too, the course she is adopting is the one best calculated to establish a habit of exhaustive observation; which is the professed aim of these lessons.  To tell a child this and to show it the other, is not to teach it how to observe, but to make it a mere recipient of another’s observations:  a proceeding which weakens rather than strengthens its powers of self-instruction—­which deprives it of the pleasures resulting from successful activity—­which presents this all-attractive knowledge under the aspect of formal tuition—­and which thus generates that indifference and even disgust not unfrequently felt towards these object-lessons.  On the other hand, to pursue the course above described is simply to guide the intellect to its appropriate food; to join with the intellectual appetites their natural adjuncts—­amour propre and the desire for sympathy; to induce by the union of all these an intensity of attention which insures perceptions both vivid and complete; and to habituate the mind from the beginning to that practice of self-help which it must ultimately follow.