212 THE ATOMIC WEIGHTS. 



ZIRCONIUM. 



The atomic weight of zirconium has been determined by 

 Berzelius, by Hermann, and by Marignac. Berzelius* ig- 

 nited the neutral sulphate, and thus ascertained the ratio in 

 it between the ZrO., and the SO 3. Putting SO3 at 100, he 

 gives the following proportional quantities of ZrO, : 



Mean, 75.853, =h .023 



Hence Zr = 89.255, ± .039 ; or, if = 16, then Zr = 

 89.461. 



Hermann's t estimate of the atomic weight of zirconium 

 was based upon analyses of the chloride, concerning which 

 he gives no details or weighings. From sublimed zirconium 

 chloride he finds Zr = 831.8, when = 100 ; and from two' 

 lots of the basic chloride 2ZrOCl,.9H,0, Zr = 835.65 and 

 851.40 respectively. The mean of all three is 839.62; 

 whence, with modern formulse and = 15.9633, Zr becomes 

 = 89.354. 



Marignac's results I were obtained by analyzing the double 

 fluoride of zirconium and potassium. His weights are as 

 follows : 



i.ooo grm. gave .431 grm. ZiO., and .613 grm. K2SO^. 

 2.000 " .864 " 1.232 " 



.654 " .282 " .399 

 5.000 " 2.169 " 3-0/8 " 



These figures give us three ratios. A, the ZrO. from 100 



* Poggend. Annal., 4, 126. 1825. 



fjourn. fiir Prakt. Chem., 31, 77. Berz. Jahresb,, 25, 147. 



J Ann. Chim. Pliys., (3,) 60, 270. 1S60. 



