For some reactions it is advantageous to heat the mixture, and the following arrangement is very satisfactory for this purpose. The bottle H is
wrapped with moistened asbestos paper to a thickness of about 3 mm. and the paper is then allowed to dry. When the asbestos is thoroughly dry the
bottle is wound with a coil of No. 24 Nichrome wire, beginning the coil at the bottom of the bottle and making the turns about 9 mm. apart. The wire
is then covered with a 3-mm. layer of asbestos, which is moistened and allowed to dry, after which the wire is wound around the bottle in another coil
from top to bottom. The second coil is covered with asbestos as before, and the ends of the wire are connected to the terminal wires from a source of
current. These wires are led along the bottle to the neck and held by means of tape in order to avoid excessive shaking. A variable resistance in the
circuit is used to regulate the temperature.
|
