94 ,THE ATOMIC WEIGHTS. 



1. 4195 grm. T1,^S0^ gave .6534 grm. BaSO^. 217.248 



I. 1924 " .5507 " 216.524 



.8560 " .3957 " 216.325 



Mean, 216.699 



Including Lamy's single result, as of equal weight, we get 

 a mean of 216.754. ± .1387. 



From the chloride series we have these results, with the 

 ratio stated as usual : 



.2984 grm. TlCl gave .1791 grm. AgCl. 166.611 



.5452 " .3278 . " 166.321 



Mean, 166.465, ± .097 



Lamy's mean was 166.915, dz .1905. Both means com- 

 bined give a general mean of 166.555, ± .0865. 



Werther's* determinations of iodine in thallium iodide 

 were made by two methods. In the first series Til was de- 

 composed by zinc and potassium hydroxide, and in the 

 filtrate the iodine was estimated as Agl. One hundred 

 parts of Agl correspond to the amounts of Til given in the 

 last column : 



.085 



In the second series the thallium iodide was decomposed 

 by ammonia in presence of silver nitrate, and the resulting 

 Agl was weighed. Expressed according to the foregoing 

 standard the results are as follows : 



1.375 grm. Til gave .978 grm. Agl. Ratio, 140.593 

 1.540 " 1.095 " 140.639 



1.380 " .981 " 140.673 



Mean, 140.635, zb -016 



General mean of both series, 140.648, dr .016. 



* Journ. fiir Prakt. Chcm., 92, 128. 1864. 



