r in weight and,
through the property of the wood, in color also.

The child has to take a tablet and rest it delicately on the inner
surfaces of his four fingers, spreading them well out. This will be
another opportunity of teaching delicate movements.

The hand must move up and down as though to weigh the object, but the
movement must be as imperceptible as possible. These little movements
should diminish as the capacity and attention for perceiving the
weight of the object becomes more acute and the exercise will be
perfectly performed when the child comes to perceive the weight
almost without any movement of the hands. It is only by the repetition
of the attempts that such a result can be obtained.

Once the children are initiated into it by the teacher, they blindfold
their eyes and repeat by themselves these exercises of the _baric
sense_. For example, they lay the heavier wooden tablets on the right
and the lighter on the left.

When the child takes off the handkerchief, he can see by the color of
the pieces of wood if he has made a mistake.

* * * * *

A long time before this difficult exercise, and during the period when
the child is working with the three sorts of geometrical solids and
with the rough and smooth tablets, he can be exercising himself with a
material which is very attractive to him.

This is the set of tablets covered with bright silk of shaded colors.
The set consists of two separate boxes each containing sixty-four
colors; that is, eight different tints, each of which has eight shades
carefully graded. The first exercise for the child is that of _pairing
the colors_; that is, he selects from a mixed heap of colors the two
tablets which are alike, and lays them out, one beside the other. The
teacher naturally does not offer the child all the one hundred and
twenty-eight tablets in a heap, but chooses only a few of the brighter
colors, for example, red, blue and yellow, and prepares and mixes up
three or four pairs. Then, taking one tablet--perhaps the red one--she
indicates to the child that he is to choose its counterpart from the
heap. This done, the teacher lays the pair together on the table. Then
she takes perhaps the blue and the child selects the tablet to form
another pair. The teacher then mixes the tablets again for the child
to repeat the exercise by himself, _i.e._, to select the two red
tablets, the two blue, the two yellow, etc., a