48 THE ATOMIC WEIGHTS. 



Stas* gives the following series : 



145-453 

 145.468 



145-465 

 145.469 



145.443 



Mean, after reducing 

 to vacuum standard, 145.4526. ±: .0030 



Combining, we have as follows : 



Penny, 1st series 145. 4164, dr .0015 



" 2d " 145.410, d= .0026 



Stas 145.4526, dz .0030 



General mean 145.4185, =b .0012 



We have now, apart from the determinations of gaseous 

 density, nine ratios, representing one hundred and fourteen 

 experiments from which to calculate the atomic weight of 

 nitrogen. Let us first collect and number these ratios : 



(I.) Ag : AgNOj : : 100 : 157.479. ^ -0003 

 (2.) AgNOj : AgCl : : 100 : 84.3743, ± .0025 

 (3.) AgNO.^ : KCl : : lOO : 43.8715, dz .0004 

 (4.) AgNOj : NH^Cl : : 100 : 31.488, zh .0006 

 (5.) Ag : NH.Cl : : 100 : 49-597, ± -OO05 

 (6.) KCl : KNO3 : : 100 : 135.6363, ± .0007 

 (7.) KCIO3 : KNO3 : : 100 : 82.500, zh .0012 

 (8.) NaCl : NaNOg : : lOO : 145. 4185, d= .0012 

 (9.) NaClOs : NaNO,, : : 100 : 79.S823, i .0029 



From these ratios we are now able to deduce the molec- 

 ular weight of ammonium chloride and of the three nitrates 

 named in them. For these calculations we may use the 

 already determined atomic weights of silver, oxygen, potas- 

 sium, sodium, and chlorine, and the molecular weights of 

 silver chloride and sodium chloride. These two molecular 

 weights involve, respectively, the most probable values for 

 silver, sodium, and chlorine. We cannot, however, appro- 

 priately use the directly determined molecular weight of 

 potassium chloride, since the most probable value for the 



* Aronstein's Translation, p. 278. 



