A definite and undoubted part of the teacher's work is that of teaching an exact nomenclature.
She should, in most cases, pronounce the necessary names and adjectives without adding anything further. These words she should pronounce distinctly, and in a clear strong voice, so that the _various sounds_ composing the word may be distinctly and plainly perceived by the child.
So, for example, touching the smooth and rough cards in the first tactile exercise, she should say, "This is smooth. This is rough," repeating the words with varying modulations of the voice, always letting the tones be clear and the enunciation very distinct. "Smooth, smooth, smooth. Rough, rough, rough."
In the same way, when treating of the sensations of heat and cold, she must say, "This is cold." "This is hot." "This is ice-cold." "This is tepid." She may then begin to use the generic terms, "heat," "more heat," "less heat," etc.
_First._ "The lessons in nomenclature must consist simply in provoking the association of the name with the object, or with the abstract idea which the name represents." Thus the _object_ and the _name_ must be united when they are received by the child's mind, and this makes it most necessary that no other word besides the name be spoken.
_Second._ The teacher must always _test_ whether or not her lesson has attained the end she had in view, and her tests must be made to come within the restricted field of consciousness, provoked by the lesson on nomenclature.
The first test will be to find whether the name is still associated in the child's mind with the object. She must allow the necessary time to elapse, letting a short period of silence intervene between the lesson and the test. Then she may ask the child, pronouncing slowly and very clearly the name or the adjective she has taught: "Which is _smooth_? Which is _rough_?"
The child will point to the object with his finger, and the teacher will know that he has made the desired association. But if he has not done this, that is, if he makes a mistake, _she must not correct him_, but must suspend her lesson, to take it up again another day. Indeed, why correct him? If the child has not succeeded in associating the name with the object, the only way in which to succeed would be to _repeat_ both the action of the sense stimuli and the _name_; in other words, to repeat the lesson. But when the child has failed, we should know that he was not at that instant ready for the psychic association which we wished to provoke in him, and we must therefore choose another moment.