bead. Fused with soda upon charcoal, it is
absorbed. The sulphate fuses at first to a clear bead, which soon
spreads, and is absorbed and converted while boiling into a hepatic
mass. If this mass is taken out, placed upon a piece of polished
silver and moistened with a little water, a black spot of sulphide of
silver is left after washing off the mass with water.

Borax dissolves baryta and its compounds with a hissing noise, as well
in the flame of oxidation as in that of reduction. There is formed a
clear bead which, with a certain degree of saturation, is clear when
cold, but appears milk-white when overcharged, and of an opal, enamel
appearance, when heated intermittingly, or with a vacillating flame,
that changes frequently from the oxidating to the reducing flame.
Baryta and its compounds produce the same reactions with microcosmic
salt.

Baryta and its compounds fuse when exposed to ignition in the
oxidizing flame. Moistened with the solution of nitrate of cobalt, and
heated in the oxidation flame, it presents a bead, colored from
brick-red to brown, according to the quantity used. This color
disappears when cold, and the bead falls to a pale grey powder after
being exposed awhile to the air. When heated again, the color does not
appear until fusion is effected. If carbonate of soda is fused upon
platinum wire with so much of the sesquioxide of manganese that a
green bead is produced, this bead, when fused with a sufficient
quantity of baryta, or its compounds, after cooling, will appear of a
bluish-green, or light blue color.

(_b._) _Strontia_ (SrO).--Strontia and its compounds are analogous to
the respective ones of baryta. The hydrate of strontia has the same
properties as the hydrate of baryta, except that it is less soluble in
water. The carbonate of strontia fuses a little at a red heat, swells,
and bubbles up like cauliflower. This produces, in the blowpipe flame,
an intense and splendid light, and now produces an alkaline reaction
upon red litmus paper. The sulphate of strontia melts in the oxidation
flame upon platinum foil, or upon charcoal, to a milk-white globule.
This fuses upon charcoal, spreads and is reduced to the sulphide,
which is absorbed by the charcoal. It now produces the same reactions
upon polished silver as the sulphate of baryta under the same
conditions. By exposing strontia and its compounds upon platinum wire,
or as a splinter with the platinum tongs, to the point of the blue
f