ascertained. It consists of clay, sand, silicic acid and gypsum.

The filtrate is then poured into a cylinder capable of holding 100
cubic centimeters, and furnished with a scale; sufficient distilled
water is then added until the well-shaken fluid measures precisely 100
cubic centimeters. By means of this measuring instrument, the filtrate
is then divided into two equal portions. One of these parts is in a
beaker glass over-saturated with chemically pure chloride of ammonia,
whereby any iron of oxide present and a little dissolved alumina fall
down as deposit. The precipitate is separated by filtering, washed,
dried at 212° Fahrenheit and weighed. To the filtrate is then added a
solution of oxalate of ammonia until a white precipitate of oxalate of
lime is formed. This precipitate is separated by filtering, washed,
dried and when separated from the filter, is collected upon dark
satinized paper; the filter itself is burned and the ash added to the
oxalate of lime. This oxalate of lime is then heated to a dark red
heat in a platinum crucible with lid until the oxalate of lime is
converted into carbonate of lime. By the addition of a few drops of
carbonate of ammonia solution and another slight heating of the
crucible, also the caustic lime produced in the filter ash by heating,
is reconverted into carbonate of lime, and after cooling in the
exsiccator, the whole contents of the crucible is weighed as
carbonate of lime, after deducting the known quantity of filter ash.

Any magnesia present in the filtrate of the oxalate of lime is by the
addition of a solution of phosphate of soda separated as phosphate of
ammonia and magnesia, after having stood twenty-four hours. The
precipitate is filtered off, washed with water to which a little
chloride of ammonia is added, dried, and after calcining the fiber and
adding the filter ash, glow heated in the crucible. The glowed