(_e._) _Platinum Spoon._--When we require to fuse substances with the
acid sulphate of potash, or to oxidize them by detonation with nitrate
of potash, whereby we wish to preserve the oxide produced, we
generally use a little spoon of platinum, about from nine to fifteen
millimetres[1] in diameter, and shaped as represented in Fig. 7. The
handle of this spoon is likewise of platinum, and should fit into a
piece of cork, or be held with the forceps.

[1] The French millimetre is about the twenty-fifth part of an
English inch.

[Illustration: Fig. 7.]

(_f._) _Platinum Forceps or Tongs._--We frequently are necessitated to
examine small splinters of metals or minerals directly in the blowpipe
flame. These pieces of metallic substances are held with the forceps
or tongs represented as in Fig. 8, where _ac_ is formed of steel, and
_aa_ are platinum bars inserted between the steel plates. At _bb_ are
knobs which by pressure so separate the platinum bars _aa_, that any
small substance can be inserted between them.

[Illustration: Fig. 8.]

(_g._) _Iron Spoons._--For a preliminary examination iron spoons are
desirable. They may be made of sheet iron, about one-third of an inch
in diameter, and are very useful in many examinations where the use of
platinum would not be desirable.

(_h._) _Glass Tubes._--For the separation and recognition of volatile
substances before the blowpipe flame, we use glass tubes. These should