could have originated_, except that "in the beginning" it was called
into existence by the fiat of Him whom we Christians worship as our God,
the Creator. Thus we reach the conception of the universe as that of a
great clock gradually running down, which is certainly the antithesis of
that picture so long held before us by the advocates of the development
theory.

Uranium is a rather rare element, though known for over a hundred years,
and has an atomic weight of 238.5. In decomposing it gives off first a
helium atom, weight 4; and after this action has been repeated three
times the substance left is radium, atomic weight about 226.4. Thus
radium is simply uranium after it has lost three helium atoms. Radium in
its disintegration gives off three kinds of particles, namely, helium
atoms (positively electrified), [Greek: b]-rays or electrons, and
[Greek: g]-rays, the latter being identical with the X-rays, and having
penetrating power sufficient to carry them through six inches of lead or
a foot of solid iron. The final stage in this process of disintegration
is the ordinary element lead, in which condition the atoms seem to have
reached relative stability. Whether or not our stock of lead, with our
other common elements that are not radioactive, was originally produced
by the disintegration of these other elements, is merely a matter of
conjecture. We know nothing at all about it.

The length of time it takes for half the atoms of an element to change
is called its "life" or period. The periods of most of the radioactive
substances have been calculated, that of uranium being very long. The
calculated period of radium is 2,500 years, while that of polonium is
only 202 days, and that of niton 5.6 days. These unquestioned facts,
together with the enormous amount of heat evolved by the disintegration
of these substances (that from radium being about 250,000 times the heat