To shew the evil effects of overlooking this important law of Nature in the education of a child, we have only to attend to the painful results which would be the consequence of acting contrary to it, even in the vigorous mind of an adult. Let us for this purpose suppose a person of a powerful understanding, and a capacious mind, ushered for the first time, and for only five minutes into a crowded apartment in some eastern caravansary, or eastern bazaar, in which every thing to him was new and strange; and let us also suppose that it was imperatively demanded of him, that he should, in that short space of time, make himself acquainted with all that was going on, and be able, on his retiring, minutely to describe all that he saw. The first moment he entered, and the first strange object that caught his eye, would convince him that _the thing was impossible_. If, without such a demand, he had been introduced into such a place, and had seen various groups of strange persons differently employed, each engaged in a manner altogether new to him, and the nature of which was wholly unknown, he might look on with perfect composure, and considerable amusement, because he could attend, like the boy in the fair, either to the general mass, to isolated groups, or to individual things. He would in that case attend to no more than he was able to understand; and would placidly allow the other parts of the scene to pass without any particular attention. But the imperative injunction here supposed,--this pressure from without,--this artificial and unnatural demand upon him,--entirely alters the case. If he even attempted to make himself master of all the particulars of the scene in a circumscribed portion of time, he would find himself bewildered and confounded. The very attempt to individualize and to group so many various objects at the same moment, within such a limited period, would be enough to prostrate all the powers of his mind. He might perhaps be able to observe the persons and their costume, because varieties of persons and dresses are daily and constantly objects of observation, and are grouped without difficulty; but of their several employments, of which he was previously ignorant, he could know nothing, and on retiring, he would neither be able to remember nor to describe them. In such an experiment, it would be found, that the more anxious he was to perfect his task and to answer the demand, in the same proportion would he find himself harassed and distressed, and the powers of his mind overstretched and weakened. And if this would be the result of confounding the principles of individuation and grouping in an adult,--a person of good understanding, and of vigorous mind,--how much more hurtful must such a task be, when demanded from children or youths of ordinary capacity, during their attendance at school!