Page 118 - My FlipBook

io6 MECHANICAL DENTISTRY AND METALLURGY.

the wire coming" from the zinc of the Ijattery, attach the ends
of the wire encirchng the cast, suspending the latter in the
jar of silver cyanid solution. Then to the wire coming from
the carbon to the silver solution attach a piece of fine silver,
which is also suspended in the solution. The silver is called
the anode and the cast the cathode.* These attachments

Fig. 62.

should remain for about 48 hours, the time required for a
deposit of silver of sufficient thickness for an artificial
denture.
The Bunsen Battery is composed of an outside glass or
stone jar with dilute sulphuric acid (sulphuric acid i part
to 10 of water). In this is placed a cylinder of stout sheet
zinc, well amalgamated. A porous cup or cell is placed
within the zinc, and in this a block of carbon is gently depos-

* The conductors immersed in the liquid to be decomposed are termed
positive and negative electrodes. ' The positive electrode, or the conduc-
tor by which the current enters the liquid, is termed the anode, and that
by which it leaves, or the negative, is termed the cathode.