ATOMIC WEIGHTS 



101 



.00103 



Ladenburg was followed, in the measurement of this ratio, by Koeth- 

 ner and Aener ; ' whose observations are of the highest significance. In 

 a number of preliminary experiments they found that silver iodide, 

 precipitated from solutions of silver nitrate, was liable to contain occlu- 

 sions of the latter salt; a fact which accounts for the low values for 

 iodine found by Marignac and Stas. Their final determinations of the 

 chloride-iodide ratio are as follows, with vacuum corrections : 



Mean. 163.8070, ± .00057 



Two series of measurements of this ratio are due to Baxter," who 

 verified the occlusion of silver nitrate by silver iodide. This source of 

 error he obviated by fusing the iodide in an atmosphere containing iodine. 

 In one series, the silver iodide was first converted into bromide and 

 afterwards into chloride; in the other series the conversion was direct. 

 Baxter's determinations appear in the two following tables: 



^Liebig's Annalen, 337, 123 and 367. 1904. Ibid., 338, 362. See also Ladenburg, ibid., 338, 2.59. 

 A preliminary paper by Koethner and Aener is in Ber., 37, 2536. 1904. 



= Proc. Amer. Acad., 40, 431. 1904. Ibid., 41, 73. 1905. Journ. Anier. Chem. Soc, 26, 1593, 

 and 27, 879. 



