402 SCIENTIFIC THOUGHT. 



as a kind of revelation, and it is not surprising that it 

 came late in the course of civilisation. 1 



Nothing can have tended more in this direction than 

 the success of the Newtonian gravitation formula, and of 

 the simple laws of motion, which, at the time of the birth 

 of modern chemistry, stood firmly established as the key 

 to all problems of physical astronomy. No wonder that 

 men were on the look-out for correspondingly simple 

 perhaps analogous relations in the world of molecular 

 phenomena. One of the earliest suggestions, which came 

 forward soon after Dalton's atomic view had helped to 

 establish the prevailing rule of fixed and of multiple pro- 

 portions in the chemical combinations and reactions of 

 matter, was the idea that, as to each element belonged a 

 definite combining number, all these numbers must be the 

 multiple of the lowest among them, the equivalent or 

 is. atomic weight of hydrogen. This is Front's celebrated 



Prout's 



hypothesis, hypothesis, which had some ardent admirers, and which 

 has been repeatedly abandoned and revived in the course 

 of this century. 2 It is hardly possible to maintain it any 

 longer, since the accurate and elaborate measurements of 



1 Except indeed the Pythagorean | processes at our command could 

 notions are regarded as an anticipa- j not be broken up. This primary 

 tion of it. substance might then be either 



2 The hypothesis of Prout, pub- hydrogen, the lightest in weight of 

 lished anonymously in 1815, and ; known substances, or some other 

 warmly defended by Thomson, has j substance of which hydrogen itself 

 been again and again revived. From j was an atomic multiple. Abroad, 

 the beginning it was put forward j Prout's hypothesis was disproved 

 together with the suggestion that \ by Berzelius's accurate determine- 



the different elementary substances 

 might after all turn out to be all 

 derived from one and the same 



tions, in England by Turner's, and 

 about 1830 it fell into oblivion. It 

 was again revived in 1840 by Dumas, 



primary form of matter, and that who, as well as his followers, Lau- 

 the atoms of this might in the j rent and Gerhardt, favoured the 

 atoms of our present elements '. idea that the explanation of the 

 merely be aggregated in different different properties of chemical corn- 

 numbers and figures, held together | pounds, notably organic compounds, 

 by forces, which by the means and ; was to be found in the arrangement 



