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 Zr0 2 

 and the SO 3 . Putting S0 3 at 100, he gives the following proportional 

 quantities of Zr0 2 : 



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 sulphate. 



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 2ZrOCl 2 ,9H 2 0, 

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

 whence, with modern formulae and O = 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 : 



i.ooo grm. gave .431 grm. ZrO 2 and .613 grm. K 2 SO 4 . 



2.000 " .864 " 1.232 " 



.654 " .282 " .399 



5.000 " 2.169 3-78 " 



These figures give us three ratios. A, the Zr0 2 from 100 parts of salt; 

 B, the K 2 SO 4 from 100 parts of salt ; and C, the ZrO 2 proportional to 100 

 parts of K 2 SO, : 



A. B. C. 



43.100 61.300 70-3 10 



43.200 61.600 70.130 



43.119 61.000 70.677 



43.380 61.560 70.468 



Mean, 43.200, d= .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. fi'ir Prakt. Chem., 31, 77. Berz. Jahresb., 25, 147. 



jAnn. Chim. Phys. (3), 60, 270. 1860. 



I Lund. Arsskrift, v. 18. i88i-'82. 



