326 THE ATOMIC WEIGHTS. 



Hence we have the following percentages, reckoned on the original 

 salt: 



Ir. 2 KCL Cl,. 



39.881 30.829 29.290 

 39.890 30. 842 29.277 

 39.868 30-813 29.300 



39.876 30-835 29.289 



39.877 30-825 29.287 

 39.879 3.8n 29.310 



39.882 30.814 29.285 



39.883 30.792 29.288 



Mean, 39.880, =fc .0015 Mean, 30.820, .0037 Mean, 29.291, =b .0024 



Joly * studied derivatives of iridium trichloride. The salts were dried 

 at 120, and reduced in hydrogen. With IrCl 3 .3KC1.3H 2 he found as 



follows : 



Salt. Ir. KCl. 



1.5950 .5881 .6803 



1.6386 -6037 .7000 



2.6276 .9689 1.1231 



These data, if the weight of the salt itself is considered, give discordant 

 results, but the ratio Ir : 3KC1 : : 100 : x is satisfactory. The values of x 



are as follows : 



115.677 



115.952 



Mean, 115.848, .0583 



The ammonium salt, IrCl 3 .3NH 4 Cl, gave the subjoined data : 



Wt. of Salt. Wt. of Ir. Per cent. Ir. 



1.5772 .6627 42.017 



1.6056 .6742 41.990 



Mean, 42.003, .0094 



To sum up, the ratios available for iridium are these : 



(i.) Per cent. Ir in Am 2 IrC) 6 , 43.732, .0035 

 (2.) Per cent. Ir in K 2 IrCl 6 , 39.880, .0015 

 (3.) Per cent. KCl in K 2 IrC) 6 , 30.820, .0037 

 (4.) Per cent. C1 4 in K 2 IrCl 6 , 29.291, =b .0024 

 (5.) Per cent. Ir in Am 3 IrCl 6 , 42.003, .0094 

 (6.) Ir : 3KC1 : : 100 : 115.848, .0583 



The data for computation are 



O == 15.879, i .0003 N = 13.935, .o 21 



Cl = 35.179, .0048 KG] = 74.025, .0019 



K =. 38.817, .0051 H = i 



*Compt. Rend., no, 1131. 1890. 



