OXYGEN. 33 



based upon the density of the mixed gases obtained by the electrolysis 

 of water, gave 2.0037 ; but Morley shows that some corrections were 

 neglected. This determination, therefore, may be left out of account. 

 Now, including all data, we have a mean value for the density ratio : 



(A.) H :O: : I : 15.8948, .00048; 



or, omitting Morley's rejected series, 



(B.) H :O: : I : 15.8991, .00048. 



Correcting these by the volume ratio, 2.0028, .00004, the final result 

 for the atomic weight of oxygen as determined by gaseous densities 

 becomes : 



From A O 15.8726, =b .00058 



From B O = 15.8769, .00058 



Combining these with the result obtained from the syntheses of water, 

 rejecting nothing, we have 



By synthesis of water O = 15.8837, .00026 



By gaseous densities O = 15.8726, .00058 



General mean O = 15.8821, .00024 



If we reject Reiser's Work under the first heading, and omit Morley's 

 defective hydrogen series under the second, we get 



By synthesis of water O 15.8796, .00027 



By gaseous densities O = 15.8769, d= .00058 



General mean O = 15.8794, .00025 



Morley, discussing his own data, gets a final value of O = 15.8790, 

 .00026, a result sensibly identical with the second of the means given 

 above. These results cannot be far from the truth ; and accordingly, 

 rounding off the last decimals, the value 



= 15.879, .0003, 

 will be used in computation throughout this work. 



NOTE. A useful " short bibliography " upon the composition of water, 

 by T. C. Warrington, may be found in the Chemical News, vol. 73, pp. 

 137, 145, 156, 170, and 184. 



