180 Estimation of Nickel in Pyrrhotites and Mattes. 
perceptible. The apple- greek mrepiee of phosphate of nickel 
is partially washed, dissolved in a little dilute sulphuric acid, 
the solution rendered somitiy aaine by ammonium hydrate 
and a ome pesoinrtated by the bat 
e than retay per cent of nickel, it is 
necessa dissolve he” precipitate of phosphate of iron in 
necessary 10 acid, dilute this solution somewhat, render it nearly 
neutral by ammonium hydrate, add twenty-five or thirty cubic 
centimeters of acetic acid, and re-precipitate by phosphate of 
soda. The filtrate is added to the first filtrate. If the solution 
Tea been rendered alkaline before the addition of acetic acid, or 
if an insufficient quantity of phosphate of soda has been used 
a small amount of iron will remain in the solution, not enough, 
however, to interfere with the battery precipitation ‘of the nickel. 
The solution of phosphate of soda inal d be a saturated one, 
and, if it is heated separately, the troublesome boiling of the 
bulky precipitate is avoided. By the aid of the filter pump 
this bionagaad is readily filtered in spite of its unpromising 
Found. Theory. per cent. 
100 e. ¢. of which 1486 "150 99°06 
100c¢c  * 149 "150 99°33 
Hen © 0748 075 99°73 
To the first portion, the phosphate of soda was added first, 
and the acetic acid afterward. 
