Medical Jurisprudence And Toxicology

552 MEDICAL JURISPRUDENCE

A sudden outbreak33 of zinc poisoning occurred amongst the inmates of a large
institution near London. About 400 persons were served at tea with stewed apples
cooked in galvanized iron vessels. Within a few minutes more than 200 oi those who
partook of the stew complained of dizziness, colic and tightness m the throat. There was
some diarrhoea. Only ten persons were at all seriously ill, and all of them were able
to carry out their ordinary work next day so that obviously the effects of the poisoning
soon passed off. The chemical examination of some of the stewed apples remaining from j
the meal showed that they contained 7 grains of zinc, expressed as zinc oxide, in the
pound ; this is equivalent to 25 grains of hydrated zinc sulphate to the pound,

Poisoning "by zinc salts is very rare indeed. Accidental poisoning has
occurred from zinc sulphate having been taken in mistake for magnesium sul-
phate. Cases are recorded in which it was taken with intent to commit suicide
or to procure abortion. It has been very rarely administered homicidally.
Zinc chloride has been used suicidally, but rarely for homicidal purposes.
Poisoning by this salt has occurred from its application to a wound or to a raw
cancerous surface, from injection of a 50 per cent solution into the rectum in
mistake for glycerol,33 as also from vaginal douching with a solution of 1
drachm to 1 litre of water.34 Burnett's fluid has caused poisonous symptoms
through being mistaken for fluid magnesia.

Zinc oxide is not, as a rule, poisonous, but its fumes, when inhaled, are
highly poisonous. Zinc stearate causes poisonous symptoms in children from,
accidental inhalation of the powder, and produces interstitial pneumonia and
peribronchial inflammation. Schalepfer85 reports the case of a child, aged
7J months, who died thirty-four hours after inhaling zinc stearate. Cyanosis
and dyspnoea were the principal symptoms, and a state of ** acidosis " was
noted twelve hours before death. At the necropsy the lungs were found
voluminous. The bronchioles contained plugs of zinc stearate and mucus,
which appeared as wormlike masses. Extensive areas of emphysema were
separated from each other by small scattered, atelectatic zones.

Zinc phosphide is used by agriculturists to destroy field-rats ,'but is rarely
used as a human poison, although cases of human poisoning have occurred
recently. In his annual report for the year 1951, the Chemical Examiner,
Madras, mentions that twelve cases of human poisoning occurred during the
year under report, and describes the details of two fatal cases of poisoning
by zinc phosphide of which one was accidental and the other was suicidal.
He also mentions three fatal cases of cattle poisoning by zinc phosphide.

The salts of zinc are eliminated from the system chiefly by the bowels
and to a slight extent by the kidneys. Zinc may be found in a small amount
in the body after death o^ing to its absorption by food kept in zinc or galva-
nized iron vessels.

BISMUTH

The salts of bismuth which are commonly used in medicine are—
,«. 1- Bismuth Carbonate (Bismuth Oxycarbonate or Bismuth Subcarbonatc),
2(Bi2O£CO8), H2O.—It is a heavy, white, odourless, tasteless powder, insoluble in water,
but soluble with effervescence in nitric acid and in hydrochloric acid, It is a pharma-
copceial preparation, the dose being 10 to 30 grains. It occurs in the composition of
Trochiscus bismuthi compositus, 1\ grains being contained in each.

2. Bismuth Subnitrate (Bismuth Oxynitrate), BiONOa, HO.—It is a heavy, white
powder in minute crystalline scale. It is insoluble in water and alcohol, but soluble in
dilute nitric acid. It is known as magistery of bismuth, and is sometimes used as a
cosmetic under the name of pearl white. It is a non-official preparation, the dose being
5 to 20 grains. r '

3. Bismuth Salicylate (Bismuth Oxysalicylate or Subsalicylate), BiOCrl&Oa,—It is a

heavy, white, amorphous powder, having neither taste nor odour. It is insoluble in
water, alcohol and glycerin. It is an official preparation, the dose being 10 to 30 grains

32. Brit. Med. Jour., Feb. 3a 1923, p. 201.

33. Witthaus, Med. Juris, and Toxic., Vol. IV, p 713
34 Brit. Med. Jour., Dec. 2, 1922, Ep., p. 79.

35. Amer. Jour, of Diseases of Children, Chicago, April 1926, p. 474.