CHEMISTRY SINCE TIME OF DALTON 



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 his results seemed to disprove the hypothesis, for 

 the atomic weights of many elements differed from 

 whole numbers by more, it was thought, than the limits 

 of error of the experiments. It was noteworthy, how- 

 ever, that the confidence of Dumas was not shaken, 

 though he was led to modify the hypothesis, and, in ac- 

 cordance with previous suggestions of Clark and of 

 Marignac, to recognize as the primordial element, not 

 hydrogen itself, but an atom half the weight, or even 

 one- fourth the weight, of that of hydrogen, of which 

 primordial atom the hydrogen atom itself is com- 

 pounded. But even in this modified form the hy- 

 pothesis found great opposition from experimental ob- 

 servers. 



In 1864, however, a novel relation between the 

 weights of the elements and their other characteristics 

 was called to the attention of chemists by Professor 

 John A. R. Newlands, of London, who had noticed that 

 if the elements are arranged serially in the numerical 

 order of their atomic weights, there is a curious re- 

 currence of similar properties at intervals of eight ele- 

 ments. This so-called "law of octaves" attracted 

 little immediate attention, but the facts it connotes 

 soon came under the observation of other chemists, 

 notably of Professors Gustav Hinrichs in America, 



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