ply tests. In the case of the solid organs, dry, incinerate,
digest ash in hydrochloric acid, evaporate nearly to dryness, dilute
with water, and test.

_Tests._--Polished steel put into a solution containing a copper salt
receives a coating of metallic copper. Ammonia gives a whitish-blue
precipitate, soluble in excess. Ferrocyanide of potassium gives a rich
red-brown precipitate. Sulphuretted hydrogen gives a deep brown
precipitate.

XXVI.--ZINC, SILVER, BISMUTH, AND CHROMIUM

The salts of zinc requiring notice are the sulphate and chloride.

=Sulphate of Zinc= has been taken in mistake for Epsom salts. In large
doses it causes dryness of throat, thirst, vomiting, purging, and
abdominal pain.

_Post-Mortem Appearances._--Those of inflammation of digestive tract.

_Treatment._--Tea, decoction of oak-bark, carbonate of potassium or
sodium as antidote.

=Chloride of Zinc.=--A solution containing this substance (230 grains to
the ounce) constitutes 'Burnett's disinfecting fluid.' It is a corrosive
poison.

The symptoms are burning sensation in the mouth, throat, stomach, and
abdomen, followed by vomiting, diarrhoea, with tenesmus and distension
of the abdomen. The vomited matter contains shreds of mucous membrane
with blood. There is profound collapse, cold surface, clammy sweats,
weak pulse, with great prostration. The _treatment_ is to wash out the
stomach with large and weak solutions of carbonate of sodium.
Mucilaginous drinks may be given, and hypodermic injections of morphine
are useful to allay the pain.

_Method of Extraction from the Stomach._--Dry and incinerate the tissues
in a porcelain crucible, digest ash in water, apply tests.

_Tests._--Ammonia, a white precipitate soluble in excess, reprecipitated
by sulphuretted hydrogen; ferrocyanide of potassium, a white
precipitate; sulphuretted hydrogen, a white precipitate in pure and
neutral solutions. Nitrate of baryta will show the presence of sulphuric
acid, and nitrate of silver of hydrochloric acid.

=Silver.=--Nitrate of silver is a powerful irritant.

_Tests._--Black precipitate with sulphuretted hydrogen; white with
hydrochloric acid.

_Treatment._--Common salt.

Chronic nitrate of silver poisoning is characterized by _argyria_. The
gums show a blue line, which is darker than that produced by lead, and
the skin presents a greyish hue, which is permanent.

=Bismuth.=--The bismuth salts are not poisonous, but may contain arsenic
as