Medical Jurisprudence And Toxicology

CHAPTER XXIQ

IRRITANT POISONS

Irritant poisons are those which, by their specific action, set up inflam-
mation in the gastro-intestinal canal.

General Symptoms.—The symptoms are delayed from half an hour to
an hour or more. These are burning pain, difficulty in swallowing, feeling
of constriction in the throat and oesophagus, severe pain in the stomach,
intense thirst, nausea and violent, persistent vomiting. The vomited matter
at first contains food, then becomes bilious and lastly contains altered blood.
There is purging accompanied by tenesmus and pain, and tenderness over
the abdomen; the stools may contain mucus and blood. There is dysuria.
Collapse sets in, when the skin is cold and clammy, and the pulse is quick,
feeble and intermittent. Cramps also occur in the legs. Sometimes, con-
vulsions occur before death, which may take place at once from shock, or
from exhaustion in one to four days.

If the patient survives for some time reaction sets in, consequently the
skin becomes hot and dry with a rise of temperature, but death may occur
later from stricture of the oesophagus.

Diagnosis.—Irritant poisoning has to be diagnosed from certain diseases,
such as cholera, acute gastritis, acute gastro-intestinal catarrh, peritonitis,
colic, and rupture of the stomach.

A. INORGANIC

I. NON-METALLIC POISONS

PHOSPHORUS

There are two varieties of phosphorus, white and red. The white
variety ordinarily occurs in the form of white, waxy, translucent cylinders.
On exposure to light it becomes yellow. It is insoluble in water, somewhat
soluble in alcohol and ether, and also to-a slight extent in fatty and ethereal
oils, but readily dissolves in carbon bisulphide. When exposed to the air
it slowly oxidizes and emits white fumes, which have a garlic-like odour,
and are luminous in the dark. At 34°C. it ignites in the air, burning with
a very white flame. On account of the ease with which phosphorus under-
goes oxidation it is always preserved under water.

White phosphorus is very poisonous, and is used in preparing vermin
paste for the destruction of rats and other vermin. This paste contains one
to four per cent phosphorus mixed with oil, flour, sugar and some pigmentT
probably indigo. Phosphorus is occasionally used in the manufacture of fire-
works and gunpowder. It is also used in the manufacture of lucifer matches,
and enters into the composition with which these matches are tipped.

The organic phosphorus compounds, such as parathion (diethyl-para-
nitrophenyl thiophosphate), H.E.T.R (hexaethyl tetraphosphate), T.EPP.
(tetraethyl pyrophosphate), O.M.P.A. or schradan (octamethyl pyrophos-
phoramide) and Mipafox [bis- (mono-isopropylamino) -fluorophosphine oxide]
are used as insecticide^ in agriculture. They are highly poisonous to man.
These substances like D.FP. (di-isopropyl-fluorophosphonate) cari^e mhibi-
tion of tfae enzyme cholinesterase, the effects of which produce --
symptoms,

Red phosphorus is a violel-*ed, solid Bpjss^sajd is prepared by
the white variety ^t a temperatcg^of 24§°C.^fee^|DC., in art sifebaospfere of
nitrogen or carbon* dioxide. K^'& ' xix&lid^ bisidpfcdtcte,