, could be
demonstrated in a more obvious and conclusive manner than by mere
analysis; that is, they can be converted and reconverted into each
other without addition and without subtraction.

In cyanuric acid, hydrated cyanic acid, and cyamelide, we have three
such isomeric compounds.

Cyanuric acid is crystalline, soluble in water, and capable of
forming salts with metallic oxides.

Hydrated cyanic acid is a volatile and highly blistering fluid,
which cannot be brought into contact with water without being
instantaneously decomposed.

Cyamelide is a white substance very like porcelain, absolutely
insoluble in water.

Now if we place the first,--cyanuric acid,--in a vessel hermetically
sealed, and apply a high degree of heat, it is converted by its
influence into hydrated cyanic acid; and, then, if this is kept for
some time at the common temperature, it passes into cyamelide, no
other element being present. And, again inversely, cyamelide can be
converted into cyanuric acid and hydrated cyanic acid.

We have three other bodies which pass through similar changes, in
aldehyde, metaldehyde, and etaldehyde; and, again two, in urea and
cyanuret of ammonia. Further, 100 parts of aldehyde hydrated butyric
acid and acetic ether contain the same elements in the same
proportion. Thus one substance may be converted into another without
addition or subtraction, and without the participation of any
foreign bodies in the change.

The doctrine that matter is not infinitely divisible, but on the
contrary, consists of atoms incapable of further division, alone
furnishes us with a satisfactory explanation of these phenomena. In
chemical combinations, the ultimate atoms of bodies do not penetrate
each other, they are only arranged side by side in a certain order,
and the properties of the compound depend entirely upon this order.
If they are made to change their place--their mode of arrangement--by
an impulse from without, they combine again in a different manner,
and another compound is formed with totally different properties. We
may suppose that one atom combines with one atom of another element
to form a compound atom, while in other bodies two and two, four and
four, eight and eight, are united; so that in all such compounds the
amount per cent. of the elements is absolutely equal; and yet their
physical and chemical properties must be totally different, the
constitution of each atom being peculiar, in one body consisting