SILVER, POTASSIUM, ETC. t 57 



H=i. <9=i6. 



Ag , 107.108, .0031 107.924 



K. 38.817,^.0051 39.112 



Na 22.881, .0046 23.048 



Cl 35.179, .0048 35-447 



Br 79.344,^.0062 79-949 



I 125.888,^.0069 126.847 



It must be remembered that tbese values represent the summing up 

 of work done by many investigators. Stas' ratios, taken by themselves, 

 give various results, according to the method of combining them. This 

 computation has been made by Stas himself, with his older determina- 

 tions, and more recently by Ostwald,* Van der Plaats,f and Thomsen, J 

 all with the standard of 16. By Van der Plaats two sets of results 

 are given : one with Stas' ratios assigned equal weight (A), and the other 

 with each ratio given weight inversely proportional to the square of its 

 mean error (B). The results of these several computations may well be 

 tabulated in comparison with the values obtained in my own general 

 discussion, thus : 



Clarke. Stas. Ostwald. V. der P., A. V.derP.,B. Thomsen. 



Ag 107.924 107.930 107.9376 107.9202 107.9244 107.9299 



39-H2 39-*37 39- I 3 61 39- T 4i4 39-HO3, 39- I 57 



23.048 23.043 23.0575 23.0453 23.0443 ' 23.0543 



d 35-447 35-457 35-45 2 9 35-45 16 35-45 6 5 35-4494 



Br 79-949 79 95 2 79-96^8 79-94Q7 79-9548 79.95 10 



I 126.847 126.850 126.8640 126.8445 126.8494 126.8556 



The agreement between the new values and the others is highly satis- 

 factory, and gives a strong emphasis to the magnificent accuracy of Stas' 

 determinations. No severer test could be applied to them. 



*Lehrbuch der allgemeinen Chemie, i, 41. 1885. 



tCompt. Rend., 116, 1362. 1893. 



t Zeitsch. Physikal. Chem., 13, 726. 1894. 



