A substance entirely different in color and properties has been
formed. Now either the sugar, the acid, or the water has
undergone a chemical change. It is, in fact, the sugar. But the
molecule is the smallest particle of sugar possible. The acid
must have either added something to the sugar molecules, or
subtracted something from them. It was the latter. Here, then, is
a force entirely different from the one which tends to reduce
masses to molecules. The molecule has the same properties as the
mass. Only a physical force was used in dissolving the sugar, and
no heat was liberated. The acid has changed the sugar into a
black mass, in fact into charcoal or carbon, and water; and heat
has been produced. A chemical change has been brought about.

From this we see that molecules are not the ultimate divisions of
matter. The smallest sugar particles are made up of still smaller
particles of other things which do not resemble sugar, as a word
is composed of letters which alone do not resemble the word. But
can the charcoal itself be resolved into other substances, and
these into still others, and so on? Carbon is one of the
substances from which nothing else has been obtained. There are
about seventy others which have not been resolved. These are
called elements; and out of them are built all the compounds--
mineral, vegetable, and animal--which we know.

8. An element is a chemically indivisible substance, or one from
which nothing else can be extracted.

A compound is a substance which is made up of elements united in
exact proportions by a force called chemism, or chemical