NOTES ON ATOMIC WEIGHTS. 



IN a former article 1 a sketch of the state of our know- 

 ledge as to the relative atomic weights of hydrogen and 

 oxygen was given. It was there shown that although the 

 great mass of the evidence was in favour of the atomic 

 weight of oxygen being about 15*88 times that of hydrogen 

 yet there was a certain amount of experimental work by 

 well-known and tried observers which seemed irreconcilable 

 with this result, the chief paper (1) being that of Professor 

 Julius Thomsen of Copenhagen, and based on the propor- 

 tion by weight in which ammonia and hydrochloric acid 

 combine to form neutral ammonium chloride. In a short 

 paper by the late Lothar Meyer (2) it was proved con- 

 clusively how little value could be attached to a determina- 

 tion of this nature however accurate and careful the mani- 

 pulative work might be. 



Any hopes which might have survived in the minds of 

 the most ardent follower of Prout, that the atomic weight 

 of oxygen is exactly sixteen times that of hydrogen, must 

 now be dispelled by the recent publications of E. W. 

 Morley (3) and of Thomsen (4) himself. The work of 

 Morley is so conclusive, and has been carried out with 

 such untiring patience and skill, that to any one who reads 

 the clear account which he gives of his methods and of the 

 various checks employed, it must be quite evident that that 

 type of worker of whom we regard Stas as the chief is not 

 yet extinct, in spite of the prevailing view that one must 

 publish as many papers as possible in the least possible 

 time before one can be said to engage in " original re- 

 search ". Morley's scheme for the complete determination 

 of the relative atomic weights of oxygen and hydrogen is 

 a most ambitious one, and, although his results are quite 

 conclusive now, it is much to be regretted that bad health 

 and other circumstances over which he had no control 

 (such as a workman pushing a brick through a wall on to a 



1 August, 1894. 



