molybdate, analysis IV. After filtering off the phosphorus 
precipitate the bases were precipitated from the filtrate by 
means of ammonia, and after the separation of traces of molyb- 
denum and the cerium metals a volumetric determination of 
Iron was obtained. 
For the separation of phosphoric acid from the bases the fol- 
lowing method was adopted. The mineral being easily soluble 
In hydrochloric acid, a solution containing little free acid was 
obtained ; this was poured into about 500 ¢.c. of boiling water 
containing enough ammonium oxalate in solution to unite with 
the bases to form oxalates ; the separation of a crystalline pre- 
Cipitate of the oxalates soon took place, which was quite free 
from phosphoric acid and contained all but traces of the bases ; 
the solution and precipitate were allowed to stand over night, 
then filtered and washed with hot water. The filtrate was 
analyses. 
* Rose, Quantitative Analyse, p. 524. 
+ Ber. der Deutsch. Chem. Geselisch., xv, 115. 
