38 JOURNAL OF THE 
some of the experiments he also precipitated the zirconium 
hydroxide by means of ammonium hydroxide and deter- 
mined the sulphuric acid in the filtrate by precipitation 
with barium chloride. 
Mats Weibull also used the sulphate and reports seven 
experiments with an entire consumption of 8.2335 grams. 
Bailey’s own determinations number eight, using in all 
more than sixteen grams. He gives full data as to his 
work, and it is well done and merits verv careful atten- 
tion. The following table is copied from his article.’ 
The figures have been recalculated to the basis of O=16. 
Mean Maximum Minimum 
Ar Cl 88.77 Sea Ligh Hermann 
ZrO, : HCl 90.14 90.98 89.29 Hermann 
KoZrFs : KeSO, 90.53 92.80 90.06 Marignac 
ZrOs.: Ke SOx 90.64 91.26: 90.24 Marignac 
KoZrFs : ZrOg 90.8 91.3 89.9 Marignac 
Zr(SO4)o : ZrO 89.45 92.65 89.27 Berzelius 
Z1(SO4)2 : ZrOo 89.48 90.38 89,13 Mats Weibull 
Zr(SO4)9 : ZrOg 90.65 90.78 90.46 Bailey 
It is manifest that the determinations based upon the 
ignition of the suiphate are the only ones worthy of fur- 
ther attention. A brief criticism of these is necessary. 
First, as to Mats Weibull, Bailey says that the tempera- 
ture used by him in freeing the sulphate from the excess 
of sulphuric acid was some 50° too low. This would of 
course give him variable and low results. Berzelius does 
not give exact data as to temperature used, but he seems 
to have heated the sulphate too high in driving off the 
excess of acid. Possibly more stress is to be laid upon 
the question of the purity of his sulphate and the correct- 
ness of the assumption that he had in hand the normal 
‘ 
sulphate. 
Bailey concludes from his experiments that the sulphate 
is stable up to 400° C., and that the excess of sulpnuric 
acid can be completely driven off by the use of a temper- 
3Chem,. News, 60, 17. 
