THE FIRST SERIES OF FINAL RESULTS. 43 



For 220 cubic centimeters the weight of dissolved AgCl is 22 x 



1000 

 0.0002S = 0.00006 gram. 



Similarly for washings Nos. 8 to 12 (0.94 liter) was found on the 



average 0.00146 gram of argentic chloride per liter (the individual 



determination being 1.47, 1.41, i-54, and 1.44 milligrams). For 940 



cubic centimeters we have ' X 0.00146 = 0.001^7 gram, and hence 



1000 



the total dissolved silver chloride = 0.00007 + 0.00006 + 0.00137 = 



0.00150. 



Altogether we now have for the total weight of argentic chloride : 



Grams. 



Weight of argentic chloride (vaccum) in crucible 13.65773 



Asbestos, etc., washed through Gooch crucible -f- .00010 



Dissolved -)- .00150 



Loss of fusion .00100 



Corrected weight of argentic chloride 13.65833 



Ratio, AgCl : NaCl = 13.65833 : 5.56991 = 100.000 : 40.7803. 



Molecular weight NaCl (if Ag = 107.93 and CI = 35.455) = 



40.7803 X I43-385 58.473 



Assumed atomic weight CI 35-455 



Hence atomic weight Na 23.018 



Most of the following determinations were essentially similar to 

 this, but a few small differences should be noted. In Experiment 27 

 the eight washings were extended over five days. In Experiment 64, 

 which must be considered as the best single experiment of all, the 

 concentrations were lowered to tenth normal, and twelve washings 

 were made, the first within three hours, the last after a day's lapse. 

 Considerable nitric acid was added to the first seven wash waters. 

 The slightly higher result of this experiment probably indicates 

 diminished occlusion of sodic nitrate. 



Three experiments were rejected, two because blackening of the 

 argentic chloride showed that the argentic nitrate in the first wash 

 waters had not been eliminated by the subsequent washing with pure 

 water, and one because of known loss of argentic chloride. These 

 oppositely erring results would have no effect on the final average if 

 they had been included ; but in such a table as this it seems advisable 

 to include only results not vitiated by known sources of error. On the 

 following page are given the final data and results of this comparison 

 of argentic and sodic chlorides. 



