NITROGEN. 



71 



The molecular Aveigbt of potassium nitrate is twice calculable, as 

 follows : 



From (7) KNO3 = 100.405, ± .0026 



From (8) " =. 100.371, ± .0059 



General mean KNO3 ; 



Hence N = 13.947, ± .0057. 

 And for sodium nitrate we have : 



From (9) NaNOg 



From (xo) " 



100.401, 



84.430, 

 - 84-433, 



.0024 



.0026 

 •0053 



General mean NaNOj = 84.431 , ± .0023 



Hence N = 13.913, ± .0052. 



There are now seven estimates of the atomic w^eight of nitrogen, to be 

 combined by means of the usual formula. 



From NH^CI N = 13.945, ± .005 1 



NH^Rr. . 

 ratio (4) . 



" (II). 

 AgN03.., 

 KNO3 . . , 



NaNO,. . 



= 13-942, ± .0077 



= 13-935, ± -0073 

 = 13.91 1, zt .0048 



= 13-945, ± -0044 

 = 13-947, ± -0057 

 = 13-913, ± -0052 



General mean N ^ ^3-935, 



.0021 



If oxygen is 16, this becomes 14.041. From Stas' data alone, Stas 

 finds 14.044 : Ostwald, 14.0410 ; Van der Plaats, 14.0421 (A), and 14.0519 

 (B) ; and Thomsen, 14.0396. The new value, representing all available 

 data, falls between these limits of variation. 



