18 THE ATOMIC WEIGHTS. 



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

 series, as follows : 



First Series. Hydrogen from Zinc and Hydrochloric Acid. 



WL of H. Wt. of O. At. Wt. O. 



9443 7-5000 15.885 



.6744 5-3555 15-882 



.7866 6.2569 I 5-99 



55 21 4.3903 15.904 



.4274 3-3997 15-909 



.8265 6.5686 15-895 



Mean, 15.8973,^.0032. 

 > 



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

 here corrected. 



Second Series. Electrolytic Hydrogen, Dried by Phosphorus Pentoxide. 



Wt. of H. Wt. of O. At. Wt. O. 



.5044 4.0095 15-898 



6325 5-0385 15-932 



.6349 5-5i7 15-913 



.55 6 4 4.4175 15-879 



7335 5-8224 15.876 



5.3181 15.885 



Mean, 15.8971,^.0064. 



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



Packed with Sodium Wire. 



Wt. of H. Wt. of O. At. Wt. O. 



.9323 7.4077 15-891 



9952 7-9045 15 885 



.3268 2.5977 15.898 



.7907 6.2798 15.884 



.7762 6.1671 15.891 



1.1221 8.9131 15-887 



Mean, 15.8893, i .0014 



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

 trace of water, estimated to be equivalent to an excess of three milli- 

 grammes in the total h}^drogen of the six experiments. Correcting for 

 this, the mean becomes = 15.899. 



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

 phorus Pentoxide. 



Wt. of H. Wt. of O. At. Wt. O. 



1.0444 8.3017 15-898 



.7704 6.1233 15.896 



.8231 6.5421 15.896 



.8872 7.0490 15.890 



9993 7-9403 15-892 



1.1910 9.4595 15.885 



Mean, 15.8929, .0013 



