The filter-paper must not be too large, but at the same time it must not be overloaded with the precipitate.
This is washed on to a filter-paper, dried, ignited, and weighed.
Dry, transfer the precipitate to a Berlin crucible, and clean the filter-paper thoroughly.
If filter-paper is not at hand, soak unsized paper to a pulp.
Immerse a piece of filter-paper and leave it in for 12 or 15 hours.
A little blood is caught on a piece of linen or filter-paper, and allowed to distribute itself in a thin layer.
At once cover the mouth of the tube with a filter-paper cap moistened with saturated aqueous solution of silver nitrate (1:1).
The pump draws the air out from the bottle, and atmospheric pressure forces the liquid through the filter-paper.
The bottom of the funnel is provided with a platinum cone, which supports the filter-paper, and prevents its breaking.
The upper edge of the filter-paper is specially liable to escape complete washing.