the aid of the magnifying glass.

_Lead_, or its chloride, sublimes like tellurium, and, like that
substance, fuses into globules or drops.

_Bismuth_, or its sulphide, sublimes into an orange or brownish
globules, when it is melted, as directed above, for tellurium. The
color of the bismuth and lead oxides are somewhat similar, although
that of the latter is paler.

If any mineral containing _fluorine_, is fused, first with the
microcosmic salt bead, then put into the tube, and the flame of the
blowpipe be directed _into_ the tube upon the bead, hydrofluoric acid
is disengaged and attacks the inside of the tube. The fluoride of
calcium, or fluorspar, may be used for this experiment.

During the roasting, a brisk current of air should be allowed to pass
through the tube, whereby unoxidized matter may be prevented from
volatilization, and the clogging up of the substance under examination
be prevented.

3. EXAMINATIONS UPON CHARCOAL.

In making examinations upon charcoal, it is quite necessary that the
student should make himself familiar with the different and
characteristic appearances of the deposits upon the charcoal. In this
case I have found the advice given by Dr. Sherer to be the best; that
is, to begin with the examination of the pure materials first, until
the eye becomes familiarized with the appearances of their
incrustations upon charcoal.

The greater part of the metals fuse when submitted to the heat of the
blowpipe, and if exposed to the outer flame, they oxidize. These
metals, termed the noble metals, do not oxidize, but they fuse. The
metals platinum, iridium, rhodium, osmium and palladium do not fuse.
The metal osmium, if exposed to the flame of oxidation, fuses and is
finally dissipated as osmic acid. In the latter flame, the salts of
the noble metals are reduced to the metallic state, and the charcoal
is covered with the bright metal.

We shall give a brief description of the appearance of the principal
elementary bodies upon being fused with charcoal. This plan is that
deemed the most conducive to the progress of the student, by
Berzelius, Plattner, and Sherer. Experience has taught us that this
method is the most efficient that could have been devised as an
initiatory exercise for the student, ere he commences a more concise
and methodical method of analysis. In these reactions upon charcoal,
we shall follow nearly the language of Plattner and Sherer.

SELENIUM is not difficult of f