The ferrotype and how to make it - The Grian Press

SILVER. 73
a metallic powder—with bicarbonate of soda it is
precipitated as a carbonate of silver.
When desirable to reduce silver from a so-
Intion to a metallic state, the quickest and best
way is to measure the solution, and put in a widemouth
bottle or into an evaporating dish, and for
every fifty ounces of solution add three ounces of
sulphuric acid, and three ounces of clean zinc in
strips—iron, if more convenient, would answer
the same purpose—the zinc or iron should be
placed in the silver solution first, and then the
acid i^art at a time ; this part of the process
should be done, out of doors, or in a strong draft,
to carry off the horrible fumes which arise ; the
precipitate forms rapidly on the zinc, and should
from time to time be rubbed or scraped off. As
soon as ebullition ceases, add more acid ; at the
last, it is well to test the solution to ascertain if
the operation is complete, which can be done by
taking a small quantity of the solution, a test-
tube, and add a drop or two of hydrocloric acid,
or a pinch of common salt; if a white precipitate
is formed, th< re still remains silver in the so-
lution, to reduce which add more acid and clean
the zinc.
After the silver has been precipitated, remove
the remaining pieces of zinc or iron, and
allow the sediment to settle, after which pour
off the liquid, and wash the precipitate two or
three times with clean water until blue litmus
paper ceases to turn red in the liquid, each time