The second remark which we would here make is, that Nature, in most cases, appears to put much more value on the inferences, or lessons, drawn from the knowledge we have acquired, than she does upon the knowledge itself. For example, in the case of the infant burning its finger, the circumstance itself will soon be forgotten; but the inference, or the impression acquired by its means, will remain. And when at any subsequent period it avoids fire or flame, its mind is not so much occupied by the abstract truth that flame will burn, as by the lesson learned from that truth, that it should not meddle with it. This inference it now practically applies to its present situation. That the abstract truth,--the knowledge originally derived from the fact,--is included in the lesson, may be quite true; but what we wish at present more particularly to point out is, that _it is seldom adverted to by the infant_. The inference,--the lesson which the truth suggested,--is all that the child thought of. That alone is the fabric which Nature has been employed in rearing; and the original truth has been used merely as scaffolding for the purpose. The edifice itself, accordingly, having been completed, the scaffolding is allowed to fall, as having answered its design. The same conclusion may be come to, by attending to the circumstances connected with the operation of the principle in adults.--The person who returned for his great-coat or umbrella after having drawn the inference from the appearance of the sky, thought only of the coming shower; and we could easily suppose a case, where the original indication of the sky might be totally forgotten, while the full impression that it would rain might still continue. In like manner, the mariner, in the bustle of preparation, thinks only of the dreaded storm, while the original circumstance,--the knowledge from which the inference was drawn,--is now unheeded, or entirely forgotten. The other circumstance to which we would here solicit attention, as proving the same thing, is one to which we formerly alluded. It is the remarkable fact, that knowledge, of whatever kind, when it is practised, becomes more and more familiar and useful; while that which is not acted upon, is soon blotted from the memory and lost. Writing, arithmetic, and spelling, not to speak of grammar, geography, and history, when not exercised in after life, are frequently found of no avail, even at times when they are specially required.--Why is this? They were once known. The knowledge was communicated at a time when the mind and memory were best fitted for receiving and retaining them. But Nature in this, as in every other instance, has been true to herself; and the knowledge which is not used has been blighted, and at last removed from the memory and lost.