is called _bass_.
_Grave_ tones were so called by the Greeks because they seemed
heavy and to incline downward. Sounds seem to be subject to the
action of gravity; so that some rise and others fall. Baudelaire,
speaking of the prelude to _Lohengrin_, remarks: 'I felt myself
_delivered from the bonds of weight_.' And when Wagner sought to
represent, in the highest regions of celestial space, the
apparition of the angels bearing the Holy Grail to earth, he uses
very high notes, and a kind of chorus played exclusively by the
violins, divided into eight parts, in the highest notes of their
register. The descent to earth of the celestial choir is rendered
by lower and lower notes, the progressive disappearance of which
represents the reascension to the ethereal regions.

"Sounds seem to rise and fall; that is a fact. It is difficult to
explain it. Some have seen in it a habit derived from the usual
notation by which the height of the note corresponds to its
height in the score. But the impression is too deep and general
to be explained by so superficial and recent a cause. It has been
suggested also that high notes are generally produced by small
and light bodies, low notes by heavy bodies. But that is not
always true. It has been said, again, that high notes in nature
are usually produced by highly placed objects, while low notes
arise from caves and low placed regions. But the thunder is heard
in the sky, and the murmur of a spring or the song of a cricket
arise from the earth. In the human voice, again, it is said, the
low notes seem to resound in the chest, high notes in the head.
All this is unsatisfactory. We cannot explain by such coarse
analogies an impression which is very precise, and more sensible
(this fact has its importance) for an interval of half a tone
than for an interval of an octave. It is probable that the true
explanation is to be found in the still little understood
connection between the elements of our nervous apparatus.

"Nearly all our emotions tend to produce movement. But education
renders us economical of our acts. Most of these movements are
repressed, especially in the adult and civilized man, as harmful,
dangerous, or merely useless. Some are not completed, others are
reduced to a faint incitation which externally is scarcely
perceptible. Enoug