Articles from Aids To Forensic Medicine And Toxicology
Incised Wounds And Those Accompanied By Solution Of Continuity
Potash Soda And Ammonia
Detection Of Poisons
Examination Of Persons Of Unsound Mind
Wounds And Mechanical Injuries
The Mineral Acids
=Oxalic Acid= is used by suicides, though not often by murderers. The
crystals closely resemble those of Epsom salts or sulphate of zinc;
oxalic acid has been taken in mistake for the former. It is in common
use for cleansing brass, in laundry work, for dyeing purposes, and
especially for bleaching straw hats.
Symptoms.--If a concentrated solution be taken, it acts as a
corrosive, causing a burning acid, intensely sour taste, which comes on
immediately, great pain and tenderness and burning at pit of stomach,
pain and tightness in throat. Vomiting of mucus, bloody or dark
coffee-ground matters, purging and tenesmus, followed by collapse,
feeble pulse, cyanosis and pallor of the skin; also swelling of tongue,
with dysphagia. In some cases cramps and numbness in limbs, pain in head
and back, delirium and convulsions. May be tetanus or coma. If taken
freely diluted, the nervous symptoms predominate, and may resemble
narcotic poisoning. Sometimes almost instant death.
Post-Mortem Appearances.--Mucous membrane of mouth, throat, and
gullet, white and softened, as if they had been boiled; there are often
black or brown streaks in it. Stomach contains dark, grumous matter, and
is soft, pale, and brittle. Intestines slightly inflamed, stomach
sometimes quite healthy.
Treatment.--Warm water, then chalk, carbonate of magnesium, or
lime-water, freely. Not alkalies, as the oxalates of the alkalies are
soluble and poisonous. Castor-oil. Emetics, but not stomach-pump.
Fatal Dose.--One drachm is the smallest, but half an ounce is usually
Method of Extraction from the Stomach.--Mince up the coats of the
stomach and boil them in water, or boil the contents of the stomach and
subject them to dialysis. Concentrate the distilled water outside the
tube containing the vomited matters, etc., and apply tests.
Tests.--White precipitate with nitrate of silver, soluble in nitric
acid and ammonia. When the precipitate is dried and heated on
platinum-foil, it disperses as white vapour with slight detonation.
Sulphate of lime in excess gives a white precipitate, soluble in nitric
or hydrochloric acid, but insoluble in oxalic, tartaric, acetic, or any
=Oxalate or Binoxalate of Potash= (salts of sorrel or salts of lemon) is
almost as poisonous as the acid itself.
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