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ON CLAKmCATION.
101
of the instrument, will answer as well as the strainer. This
instrument is called a pei'colator. Having let the ingre
dients be acted upon, macerate for the time we have
named—introduce them into the percolator, and slightly
press them upon the partition. Any portion of the liquid
used in the maceration, not absorbed by the powder,
should be jjoured upon the mass in the instrument, .and
allowed to percolate. You must now gradually pour into
the percolator sufficient ofthe alcohol, or other liquid to be
filtered, to drive before it, or displace, the liquid contained
in the mass; the portion introduced must in like manner be
displaced by another j)ortion ; and so on, till you obtain the
required quantity of filtered liquor. Tins extract is called
tincture. In case the liquor which first passes through,
should be thick and turbid, you must again introduce it
into the instrnment, and be very careful not to have the
powder too coarse or loosely pressed, oiW it will permit the
liquid to pass too quickly, and on the other hand it should
not be too fine and compact, or it may ofter an unnecessaiy
resistance. Should the liquor flow too rapidly, you must
return it to the instrument, and close it beneathfor a time,
and thus permit the finer parts of the powder to subside,
and cause a slower percolation. If j'ou have sufficient
time, you can avoid the trouble of going through the pro
cess of displacement, by simply macerating the articles
for two weeks, being careful to stir them up thoroughly
once in every 24 hours.
6, On Clarification.
On the Avhole, clarification is preferable for syrups to
filtration. They need only be beaten up while cold with a
little white of egg, and then heated; a scum rises which
mustbe removed as soon as it becomes consistent, and the