14 JOURNAL OF THE 
and washing the mass. The particles settle best from 
hot water. After a while they settle slowly. It is best 
to use two or three settling jars, pouring off from the 
first to the others before a second washing is added from 
the casserole. Nearly all settles in the first jar and that 
which settles more slowly may be allow to take its time 
inthe other jars. After a while the disintegration may 
be helped by breaking with a glass rod or rubbing with 
a pestle. Five gr six gallons of water should be used 
in washing as ‘this removes the sodium silicate and it is 
far easier and better to get ridof itin this way than to 
be worried by its presence later on. Of course it is_ not 
entirely removed and some little of the zirconate is also 
lost. | ’ 
After washing the sodium zirconate must be de- 
composed by the ,addition of hydrochloric acid. Strong 
acid is used and it is boiled with the zirconate in the 
casserole used for washing. Usually all dissolves up ex- 
cepta few grams of undecomposed zircon. It is not 
necessary to filter the solution. It may be immediately 
transferred toa large evaporating dish and carried down 
to dryness, first over the naked flame and then, as silica 
etc., begin to separate out, on the sandbath. It is neces- 
sary to watch the temperature of the latter and to stir 
the mass up occasionally to prevent overheating but a 
great deal of time may thus be saved. It is usually pos- 
sible to begin a fusion in the morning and have the hy- 
drochloric acid solution of it ready for evaporation before 
the day’s work is over. 
If the washing was well-done the amount of silica sep- 
arating is not large. Hydrochloric acid is added to the 
dried mass, then water and it is filtered. The clear fil- 
trate is again evaporated to dryness to remove the last 
traces of silica. We have uniformly adopted this precaution 
but seldom found any silica separated by the last evap- 
oration. After this second evaporation and filtration the 
solution is ready for the separation of the iron. 
