Last of all comes the _fourth_, or supplementary step in this beautiful educational process of Nature. It consists in gradually training her pupil to _communicate the knowledge and experience which he has attained_.--It is probable that Nature begins this part of her process before the child has acquired the use of language;--but as it is by language chiefly that man holds fellowship with man, it is not till he has learned to speak that the mental exercise on which its success depends, becomes sufficiently marked and obvious. It consists, not in the acquisition of language so much, as in the use of language after it has been gained. The pupil is for this purpose prompted by Nature to think and to speak at the same moment;--mentally to prepare one sentence, while he is giving utterance to its predecessor. That this is not the result of instinct, but is altogether an acquisition made under the tuition of Nature by the mental exertions of the infant himself, is obvious from the fact, that he is at first incapable of it, and never pronounces three, and very seldom two words consecutively without a pause between each. This the child continues to do after he is perfectly familiar with the meaning of many words, and after he can also pronounce each of them individually. In giving utterance to the first words which he uses, there is an evident suspension of the mind in regard to every thing else. His whole attention appears to be concentrated upon the word and its pronunciation. He cannot think of any thing else and pronounce the word at the same time; and it is not till after long practice that he can utter two, three, or more words in a sentence, without hesitation and a decided pause between them. It is only by degrees that he acquires the ability to utter a phrase, and at last a short sentence, without interruption. Nature prompts the child to this exercise, which from the first attempt, to the full flow of eloquence in the extemporaneous debater, consists simply in commanding and managing one set of ideas in the mind, at the moment the person is giving utterance to others. This cannot be done by _the child_, but it is gradually acquired by _the man_; and we shall see in its proper place, that this acquisition is entirely the result of a mental exercise, such as we have here described, and to which various circumstances in childhood and youth are made directly subservient.