Articles from Aids To Forensic Medicine And Toxicology
Petroleum And Paraffin-oil
Duty Of Practitioner In Supposed Case Of Poisoning
Evidence Of Poisoning
Sale Of Poisons; Scheduled Poisons
Mercury And Its Preparations
The most important salt of mercury, toxicologically, is corrosive
sublimate. Other poisonous preparations are red precipitate, white
precipitate, mercuric nitrate, the cyanide and potassio-mercuric iodide.
Calomel has very little toxic action. Metallic mercury is not poisonous,
but its vapour is.
=Corrosive Sublimate= (perchloride of mercury) is in heavy colourless
masses of prismatic crystals, possessing an acrid, metallic taste. It is
soluble in sixteen parts of cold and two of boiling water. Soluble in
alcohol and ether, the latter also separating it from its solution in
Symptoms come on rapidly. Acrid, metallic taste, constriction and
burning in throat and stomach, nausea, vomiting of stringy mucus tinged
with blood, tenesmus, purging. Feeble, quick, and irregular pulse,
dysuria with scanty, albuminous or bloody urine or total suppression.
Cramp, twitches and convulsions of limbs, occasionally paralysis. In
poisoning from the medicinal use of mercury, there may be salivation, a
coppery taste in the mouth, peculiar foetor of breath, tenderness and
swelling of mouth, inflammation, swelling and ulceration of gums
(cancrum oris), a blue line on the gums, and the loosening of teeth.
Mercury is less quickly eliminated from the body than arsenic. In
chronic cases 'mercurialism,' 'hydrargyrism,' 'ptyalism,' or
'salivation,' including most of the symptoms enumerated above. May get
eczema mercuriale and periostitis. Profound anĉmia often a prominent
symptom; neuritis not uncommon. If fumes of mercury inhaled, mercurial
Post-Mortem Appearances.--Corrosion, softening, and sloughing
ulceration of stomach and intestines. The mucous membrane of the
oesophagus and stomach is often of a bluish-grey colour. The large
intestine and rectum are often ulcerated and gangrenous. Inflamed
condition of urinary organs, with contraction of the bladder.
Treatment.--Encourage or produce vomiting. Albumin, as white of egg,
gluten, or wheat flour, is the best antidote. Demulcent drinks, milk,
and ice. Stomach-tube to be used with care, owing to softened state of
gullet and stomach.
Fatal Dose.--Three grains in a child.
Fatal Period.--Half an hour the shortest.
Method of Extraction from the Stomach.--A trial test may be made of
the contents of the stomach with copper-foil. If mercury is found, the
contents of the stomach may be dialyzed, the resulting clear fluid
concentrated and shaken with ether, which has the power of taking
corrosive sublimate up, and thus separating it from arsenic and other
metallic poisons. The ether allowed to evaporate will leave the
corrosive sublimate in white silky-looking prisms. Suppose no mercury is
found in the dialyzed fluid, owing to the fact that corrosive sublimate
enters into insoluble compounds with albumin, fibrin, mucous membrane,
gluten, tannic acid, etc., we must dry the insoluble matter, and heat it
with nitro-hydrochloric acid until all organic matter is destroyed and
excess of nitric acid expelled. The residue dissolved in water,
filtered, and tested with copper-foil, etc.
Tests.--The following table gives the action of corrosive sublimate
1. With iodide of potassium Bright scarlet colour.
2. With potash solution Bright yellow colour.
3. With hydrochloric acid and First a yellowish and then a black
sulphuretted hydrogen colour.
4. Heated in a reduction-tube Melts, boils, is volatilized, and forms
a white crystalline sublimate.
5. With ether Freely soluble; the ethereal solution,
when allowed to evaporate
spontaneously, deposits the salt in
white prismatic crystals.
6. Heated with carbonate of Globules of metallic mercury are
sodium in a reduction-tube produced.
A very simple process for detecting corrosive sublimate is to put a drop
of the suspected solution on a sovereign and touch the gold through the
solution with a key, when metallic mercury will be deposited on the
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