A pair of _scissors_ is required to trim the wick of the and for the
trimming of the edge of platinum foil.

A small _spatula_ should be kept for the purpose of mixing substances
with fluxes.




THE REAGENTS.


Those substances which possess the property of acting upon other
substances, in such a characteristic manner that they can be
recognized, either by their color, or by their effervescence, or by
the peculiar precipitation produced, are termed _reagents_. The
phenomena thus produced is termed _reaction_. We use those reagents,
or _tests_, for the purpose of ascertaining the presence or the
absence of certain substances, through the peculiar phenomena produced
when brought in contact with them.

The number of reagents employed in blowpipe analysis is not great, and
therefore we shall here give a brief description of their preparation
and use. It is indispensably necessary that they should be chemically
pure, as every admixture of a foreign substance would only produce a
false result. Some of them have a strong affinity for water, or are
deliquescent, and consequently absorb it greedily from the air. These
must be kept in glass bottles, with glass stoppers, fitted air-tight
by grinding.