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ELISHA MITCHELL SCIENTIFIC SOCIETY. o7 
drobromic acid by the Zr(OH), the solution first becomes 
straw colored then a deeper red depending upon the time 
of the heating. This is evidently due to bromine from 
the decomposition of some hydrobromic acid by organic 
matter in the air. 
A difficult problem was the removal of the strong hy- 
drobromic acid mother liquor and the free bromine nearly 
always present with the crystals. Of the methods tried 
to effect this none proved satisfactory. The crystalline 
mass wads in one case six times washed with ether, the 
yellowish red solution, due to dissolved bromine, being 
decanted. Filtering proved too slow permitting a rather 
lone exposure of the crystals to the moisture of the air. 
After this washing with ether the crystals still slightly 
yellow colored were placed ina ‘‘vacuum’”’ desiccator for 
the removal of the remaining ether. ‘I‘he small @lass dish 
containing the material was allowed to remain 36 hours 
in the vacuum desiccator. The substance was then re- 
moved, dried between filter paper and analyzed. 
Found Calc. for ZrOBrg.13H 20 
ZrO 2 24.15 24.50 24 GORA Nettie ¢ so4.0! 
Br ee eet aN Sis eee we ee tives Sted 2 31,93 
HO 124°C 24.44 
This substance gave evidence of decomposition after 
being placed in the weighing bottle. 
Another method used for the removal of bromine was 
washing the colored crystals three times with strone (48 
per cent.) solution of hydrobromic acid. Most of the 
bromine was thus removed, although the salt remained. 
shghtly vellow, possibly due to the remaining hydrobro- 
mic acid. An interruption of the work at this point re- 
quired the salt in this state tobe placea in a desiccator 
over sulphuric acid. [It remained there for sevéral days 
when the werk was resumed. AIl moisture seemed to be 
removed and great volumes of hydrobromic acid were 
given off when the desiccator was opened. The sub- 
stance had taken on a browuish-red color around the edges 
