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

water.



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 anæmia often a prominent

symptom; neuritis not uncommon. If fumes of mercury inhaled, mercurial

tremors develop.



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

with reagents:



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

gold.