THE STORY OF NINETEENTH-CENTURY SCIENCE 



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 and 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 vari- 

 ous elements. Accepting the figures given by the au- 

 thorities 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 this 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 



