The training of her pupils to _the practical use of their knowledge_, forms the _third_ department in Nature's educational process.--This is the great end which the two previous departments were designed to accomplish. This is Nature's _chief_ object;--all the others are obviously subordinate. The cultivation of the mind, and the acquisition of knowledge were necessary;--but that necessity arose from the circumstance of their being preparatory to this. Nature, in fact, appears to have stamped this department of her operations almost exclusively with her own seal;--repudiating all knowledge that remains useless, and in a short time blotting it entirely from the memory of her pupils; while that portion of their acquired knowledge, on the contrary, which is useful and is put to use, becomes in proportion more familiar, and more permanent. It is also worthy of remark, that the knowledge which is most useful, is always most easily and pleasantly acquired. The superior importance of this department of education is very observable. In the previous departments of Nature's educational process, the child was induced to _acquire_ new ideas;--in this he is prompted to _make use of them_. In the former he was taught to _know_;--in this he is trained to _act_. For example, if he has learned that his nurse is kind, Nature now prompts him to act upon that knowledge, and he accordingly strains every nerve to get to his nurse;--if he has learned that comfits are sweet, he acts upon that knowledge, and endeavours to procure them;--and if he has once experimentally learned that the fire will burn, he will ever afterwards keep from the fire.