196 THE ATOMIC WEIGHTS. 



ZIRCONIUM. 



The atomic weight of zirconium has been determined by Berzelius, 

 Hermann, Marignac, Weibull, and Bailey. Berzelius * ignited the 

 neutral sulphate, and thus ascertained the ratio in it between the ZrO^ 

 and the SO3. Putting SO3 at 100, he gives the following proportional 

 quantities of ZrO, : 



75.84 



75-92 



75.80 



75-74 

 75-97 

 75.85 



Mean, 75.853, ± .023 



This gives 43.134, ± .0142 as the percentage of zirconia in the sul^Dhate. 



Hermann's t estimate of the atomic weight of zirconium was based 

 upon analyses of the chloride, concerning which he gives no details nor 

 weighings. From sublimed zirconium chloride he finds Zr = 831.8, 

 when = 100; and from two lots of the basic chloride 2ZrOCl2.9H20, 

 Zr = 835.65 and 851.40 respectively. The mean of all three is 839.62 ; 

 whence, with modern formulae and = 15.879, Zr becomes = 88.882. 



Marignac's results J were obtained by analyzing the double fluoride of 

 zirconium and potassium. His weights are as follows : 



1. 000 grm. gave .431 grm. ZrOj and .613 grm. K.,SO^. 

 2.000 '' .864 " 1.232 " 



.654 " .282 " .399 

 5.000 " 2.169 " 3.078 " 



These figures give us three ratios. A, the Zr02 from 100 parts of salt; 

 B, the K2SO4 from 100 parts of salt ; and C, the ZrOj proportional to 100 

 parts of KsSO^ : 



43.100 

 43.200 



43.119 



43.380 



Mean, 43.200, =b .043 Mean, 61.365, =h .094 Mean, 70.396, ± 079. 



Weibull,§ following Berzelius, ignited the sulphate, and also made a 



*Poggend. Annal , 4, 126. 1825. 



t Journ. fiir Prakt. Cheni., 31, 77. Berz. Jahresb., 25, 147. 



t Ann. Chim. Phys. (3), 60, 270. 1S60. 



§ Lund. Arsskrift, V. 18. iSSi-'S2. • 



