es this.

CAPILLARY ATTRACTION.--There is a peculiar property in liquids, which
deserves attention, and should be understood, and that is the name given
to the tendency of liquids to rise in fine tubes.

It is stated that water will always find its level. While this is true,
we have an instance where, owing to the presence of a solid, made in a
peculiar form, causes the liquid, within, to rise up far beyond the
level of the water.

This may be illustrated by three tubes of different internal diameters.
The liquid rises up higher in the second than in the first, and still
higher in the third than in the second. The smaller the tube the greater
the height of the liquid.

This is called _capillary attraction_, the word capillary meaning a
hair. The phenomena is best observed when seen in tubes which are as
fine as hairs. The liquid has an affinity for the metal, and creeps up
the inside, and the distance it will thus move depends on the size of
the tube.

THE SAP OF TREES.--The sap of trees goes upwardly, not because the tree
is alive, but due to this property in the contact of liquids with a
solid. It is exactly on the same principle that if the end of a piece of
blotting paper is immersed in water, the latter will creep up and
spread over the entire surface of the sheet.

In like manner, oil moves upwardly in a wick, and will keep on doing so,
until the lighted wick is extinguished, when the flow ceases. When it is
again lighted the oil again flows, as before.

If it were not for this principle of capillary attraction, it would be
difficult to form a bubble of air in a spirit level. You can readily see
how the liquid at each end of the air bubble rounds it off, as though it
tried to surround it.

SOUND.--Sound is caused by vibration, and it would be impossible to
convey it without an elastic medium of some kind.

_Acoustics_ is a branch of physics which treats of sounds. It is
distinguished from music which has reference to the particular kinds.

_Sounds_ are distinguished from _noises_. The latter are discordant and
abrupt vibrations, whereas the former are regular and continuous.

SOUND MEDIUMS.--Gases, vapors, liquids and solids transmit vibrations,
but liquids and solids propagate with greater velocity than gases.

VIBRATION.--A vibration is the moving to and fro of the molecules in a
body, and the greater their movement the more intense is the sound. The
intensity of the sound is affected by the densit