e 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 urged its
tenability. Coming just after Davy's dissociation of some supposed
elements, the idea proved alluring, and for a time gained such
popularity that chemists were disposed to round out the observed atomic
weights of all elements into whole numbers. But presently renewed
determinations of the atomic weights seemed to discountenance this
practice, and Prout's alleged law fell into disrepute. It was revived,
however, about 1840, by Dumas, whose great authority secured it a
respectful hearing, and whose careful redetermination of the weight
of carbon, making it exactly twelve times that of hydrogen, aided the
cause.

Subsequently Stas, the pupil of Dumas, undertook a long series of
determinations of atomic weights, with the expectation of confirming the
Proutian hypothesis. But hi