83 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 54 



Mean, 132.8670, ± .0012 



Baxter aud Wilson/ analyzing lead chloride, obtained the following 

 data: 



Ag. AgCl. Ratio. 



3.62987 4.82273 132.862 



3.21408 4.27016 132.858 



3.97568 5.28272 132.876 



2.99456 3.97949 132.891 



, 2.40837 3.19909 132.832 



3.33407 4.42982 132.865 



Mean, 132.864, ± .0054 



These incidental series of values for the ratio Ag: CI: : 100 : a: now 

 combine thus : 



Ebaugh. As series 32.841, ± .0050 



Richards and Arcliibald, Cs series 32.847, ±.0024 



Archibald, Rb series 32.848, ±.0020 



Archibald, K series 32.850, ±.0012 



Lenher, Se series 32,853, ±.0060 



Baxter and Wilson, Pb series 32.864, ± .0054 



Baxter and Coffin, Co series 32.8657, ± .0034 



Baxter and Hines, Mn series 32.8670, ± .0012 



General mean 32.8562, ± .00071 



A third group of determinations is to be classed as indirect. When 

 two ratios, RCl : Ag and ECl : AgCl have been measured by the same in- 

 vestigator, but independently of each other, the cross ratio, Ag : CI : : 

 100 : X is easily calculable from them. The examples to be given presently 

 are almost self-explanatory; but the details of the determinations must 

 be sought for in tbe later sections of tbis work, on titanium, magnesium, 

 barium, cadmium, etc. 



1 Journ. Amer. Chem. Soc, 30, 187. 1908. 



