carbonic acid by combination with the oxygen of
the atmosphere; when sugar is put into water, it simply passes from the
solid to the liquid condition. If a piece of iron or steel is allowed to
rust, the surface of the iron has entered into combination with the
oxygen and water of the atmosphere, and formed a new substance. So that
a body may change from solid to liquid, as for example from ice to
water, or from liquid to a gaseous condition, as from water to steam,
and probably from a gaseous condition to an aetherial condition as we
shall see later on, but the sum-total of Matter throughout all these
changes ever remains the same. Thus, throughout all the physical and
chemical changes that Matter may undergo in the universe, there is no
actual loss in weight or quantity. Throughout the whole realm of Nature
we do not find a single instance of the production of absolutely new
Matter. We may, and can produce new combinations of the forms of Matter.
The substance so formed by chemical combination may be different from
anything that has ever been seen or produced before, but the elements of
which it is formed must have existed in some other form before its
production.

This principle is the great underlying principle of all chemical
investigation and research, and may be proved at any time by means of
the scales or balance in the laboratory. Lavoisier first made the
experiment with the scales and proved this truth by actual
demonstration.

ART. 31. _Matter is Atomic._--The hypothesis that Matter is made up of
infinitely small particles which are termed atoms, was first proposed by
the Grecian philosophers. This hypothesis has gradually taken definite
shape, but it remained for Dalton to first put the hypothesis into a
connected form, and that form is now known as Dalton's Atomic Theory.

According to this theory, an atom of hydrogen was the lightest atom
known, but comparatively recent researches by Sir W. Crookes have shown
that there are possibly in existence minute particles which are even
lighter than an atom of hydrogen. Thus Sir W. Crookes has suggested that
there are certain particles associated with an atom of hydrogen which
are 700 times less in weight than the atom itself.

Professor J. J. Thompson has further suggested that if we could divide
an atom into a thousand parts, and could take one of those parts, we
should find that this corpuscle, as he has termed it, would be the
carrier of the charges in an e