18 



THE ATOMIC WEIGHTS. 



details .as to manipulations and materials. His final results are in four 

 series, as follows : 



First Series. — Hi/dror/cn frotn Zinc and Hydrochloric. Acid. 



Wt. of H. 



•9443 

 .6744 

 .7866 

 • 5521 

 .4274 

 .8265 



Wt. of O. 

 7.5000 



5-3555 

 6.2569 



4.3903 



3-3997 

 6.56S6 



At. Wt. O. 

 15.885 

 15.882 



'5-939 



15.904 



15-909 

 '5-^95 



Mean, 15.8973,4^.0032. 



This series apjieared in the earlier paper, but with an error which is 

 here corrected. 



Third Series. — Electrolytic Hydrogen, Dried by Passage Through a Tube 

 Packed with Sodium, Wire. 



Wt. of H. 

 -9323 

 -9952 

 .3268 

 .7907 

 .7762 

 1.1221 



Wt. of O. 



7-9045 

 2.5977 

 6.2798 

 6. 1671 

 8.9131 



At. Wt. O. 



15.891 

 15 885 

 15.898 

 15-884 

 15.891 

 15-887 



Mean, 15.8893,^.0014 



At the end of this series it was found that the hydrogen contained a 

 trace of water, estimated to lie e(|uivalent to an excess of three milli- 

 o-rammes in the total liA'-drogen of tlie six experiments. Correcting for 

 this, the mean becomes = l-5.Sr79. 



Fourth Series. — Electrolytic Hydrogen, Dried over Freshly Sublimed Phos- 

 phorus Pentoxide. 



Wt. of H. Wt. of O. . 



1.0444 8.3017 



.7704 ■ 6.1233 



.S231 6.5421 



.8S72 7-0490 



.9993 7 9403 



1.1910 9-4595 



At Wt. O. 



15.898 

 15.S96 

 15.896 

 15.890 

 15.892 

 15-S85 



Mean, 15.8929,1^.001. 



