212 J. C. Draper—Preparation of Cylinders of 
distilled water added, the mixture stirred and set aside for 
twenty-four hours or longer, and when the precipitate has set- 
tled the liquid is decanted and the beaker with its contents 
set on the water bath to dry. 
8th. Pulverize the dried material in the beaker with a glass 
rod, add twenty cubic centimeters of pure hydrochloric acid 
(Merck’s), cover the beaker with a large watch glass and set on 
the water bath; when the acid has dissolved as much as it will 
take up, it is to be decanted while hot into a shallow evap- 
orating dish of about five hundred cubic centimeters capacity. 
second dose of twenty cubic centimeters of hydrochloric 
acid is added to the contents of the beaker, and when all lumps 
are broken down the mixture is transferred to the evaporating 
dish, a little hydrochloric acid being used to complete the 
transference. 
9th. For the final separation of the silica the contents of the 
dish are evaporated to dryness on the water bath, and the heat 
continued until they cease to emit acid fumes, a little distilled 
water is then added and thoroughly incorporated with the 
residue by stirring. The mixture is again evaporated to dry- 
ness at 212° F. The second drying being completed, about 
two hundred cubic centimeters of distilled water are added, 
and when all the soluble material is taken up the mixture 1s 
transferred to a filter. On the filter there remains silica an 
undecomposed zircon. In the filtrate there are zircomum 
— sodium chloride and iron chloride. 
1 
tate properly on the filter, it must be carefully transferred 
therefrom to a beaker while it is still moist by means of a glass 
rod and jet of distilled water from a washing bottle. The 
