ZIRCONIUM, 197 



similar set of experiments with the selenate of zirconium, obtaining re- 

 sults as follows : 



Sulphate. Zr(SO^ v 



1.5499 grm. salt gave .6684 ZrO 2 . 43.126 per cent. 



1-5445 " -6665 " 43- r 53 " 



2.1683 " .9360 " 43.168 " 



1.0840 " .4670 " 43.081 " 



.7913 " .3422 " 43-321 " 



.6251 .2695 " 43. 113 " 



.4704 .2027 " 43. 9i " 



Mean, 43.150, =fc .0207 



Selenate. Zr(SeO^. 



i. 02 1 2 grm. salt gave .3323 ZrO 2 . 32.540 per cent. 



.8418 " .2744 " 32.597 " 



.6035 .1964 " 32.544 " 



.8793 .2870 " 32.640 " 



.3089 " .1003 " 3 2 .470 " 



Mean, 32.558, .0192 



Bailey * also ignited the sulphate, after careful investigation of his 

 material, and of the conditions needful to ensure success. He found that 

 the salt was perfectly stable at 400, while every trace of free sulphuric 

 acid was expelled at 350. The chief difficulty in the process arises from 

 the fact that the zirconia produced by the ignition is very light, and 

 easily carried off mechanically, so that the percentage found is likely to 

 be too low. This difficulty was avoided by the use of a double crucible, 

 the outer one retaining particles of zirconia which otherwise might be 

 lost. The results, corrected for buoyancy of the air, are as follows : 



2.02357 salt gave .87785 ZrO a . 43-38i per cent. 



2.6185 " I.I3S4 " 43-36o " 



2.27709 " .98713 " 43-35 " 



2.21645 " -96152 " 43-385 " 



L75358 " .76107 " 43-402 " 



1.64065 " .7120 " 43.397 " 



2.33255 " 1.01143 " 43.36i " 



1.81105 " .78485 " 43-337 " 



Mean, 43.372, .0056 



This, combined with previous determinations, gives 



Berzelius 43. 134, .0142 



Weibull 43. 150, .0207 



Bailey 43-37 2 , .0056 



General mean 43-3 I 7, .0051 



* Proc. Roy. Soc., 46, 74. Chem. News, 60, 32. 



