The
specimen must be _repeatedly_ washed by decantation, until the
washings are perfectly free from chlorine, when the whole may be
thrown onto a filter _merely_ to drain. The turbid water which passes
through is allowed to stand so that the suspended matter may settle,
and after decanting the clear supernatant water, the residuum is again
thrown on to the filter.
The washing and getting ready for the drying oven will, in some cases,
require days to carry out, if we wish to avoid losing anything.
So far the proceeding is exactly the same, except draining on a
filter, which would be adopted for preparing for the microscope. On no
account should the opportunity be missed of mounting several slides
permanently for microscopic examination. Drawings or photographic
enlargements will render us independent of direct microscopic appeal,
which is not at all times convenient.
The substance, if drained and allowed to dry on the filter, will
adhere most tenaciously to it, so that it is better to complete the
drying in a porcelain or platinum capsule, either by swilling the
filter with a jet of water or by carefully removing with a spatula.
The most strenuous care must be used not to contaminate the specimen
with loose fibers from the filter.
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