has been displaced from its position as an undecomposable body.
Rather have the analyses of the chemist seemed to make it more
and more certain that all elementary atoms are in truth what John
Herschel called them, "manufactured articles"--primordial,
changeless, indestructible.

And yet, oddly enough, it has chanced that hand in hand with the
experiments leading to such a goal have gone other experiments
arid speculations of exactly the opposite tenor. In each
generation there have been chemists among the leaders of their
science who have refused to admit that the so-called elements are
really elements at all in any final sense, and who have sought
eagerly for proof which might warrant their scepticism. The first
bit of evidence tending to support this view was furnished by an
English physician, Dr. William Prout, who in 1815 called
attention to a curious relation to be observed between the atomic
weight of the various elements. Accepting the figures given by
the authorities of the time (notably Thomson and Berzelius), it
appeared that a strikingly large proportion of the atomic weights
were exact multiples of the weight of hydrogen, and that others
differed so slightly that errors of observation might explain the
discrepancy. Prout felt that it could not be accidental, and he
could think of no tenable explanation, unless it be that the
atoms of the various alleged elements are made up of different
fixed numbers of hydrogen atoms. Could it be that the one true
element--the one primal matter--is hydrogen, and that all other
forms of matter are but compounds of this original substance?

Prout advanced this startling idea at first tentatively, in an
anonymous publication; but afterwards he espoused it openly and