sleep. Ultimately collapse sets in, and results in death. In cases which end
in recovery, chronic peripheral neuritis may persist, ending in paralysis from
degeneration of the nerves extending upto the nerve centres.
Unusual Symptoms.—These are convulsions, lock-jaw, delirium of a
maniacal character, rise of temperature, salivation, loss of speech, ringing in
the ears, and disordered vision with intolerance to light. Death occurs from
Arseniuretted hydrogen, when inhaled in toxic amounts, acts as a direct
poison to the haemoglobin of the red blood corpuscles, producing haemolysis,
haemoglobinuria, jaundice, and sometimes anaemia. The other symptoms are
faintness, giddiness, intense headache, nausea, vomiting, burning pain in the
abdomen, pain in the loins, dark-red urine containing blood pigment and
albumin, cyanosis and collapse. Coma or delirium may precede death, which
occurs from oedema of the lungs or sudden failure of the heart.
Fatal Dose.—Three grains of arserdous oxide is the average fatal dose.
Two grains is the smallest amount known to have caused death. Recovery
has taken place after much larger doses, varying from sixty grains to two
ounces, but these are exceptional cases.
The fatal dose of arseniuretted hydrogen is uncertain. It has been
estimated that exposure to a concentration of 1 part of this gas in 20,000
parts of air for one hour is dangerous, while exposure to a concentration of
2.5 parts to 10,000 parts of air for half an hour is fatal to adults.
Fatal Period.—The average fatal period is twelve to forty-eight hours,
though death has frequently occurred within two to three hours. Hie
shortest period is forty-five minutes.4 In this case it appears that death
occurred from shock before the poison was absorbed into the system. In
mild or sub-acute cases life may be prolonged for several weeks. In one case
after a dose of 180 grains of white arsenic death did not occur until three
months and seventeen days.5 In such cases the symptoms of gastro-intestinal
irritation subside, and are usually followed by nervous affections.
Diagnosis.—Acute arsenic poisoning has to be diagnosed from cholera,
as the symptoms of both are similar in many respects, and it is possible that
mistakes may be made in diagnosis. In order to avoid police investigations
a case of acute poisoning by* arsenic is occasionally reported as that of
cholera. It is, therefore, necessary for a medical practitioner to bear in mind
the differentiating points between arsenic poisoning and cholera which are
given below in a tabulated form : —
1. Pain in the throat.
3. Vomited matter.
Contains mucus, bile and streaks
High coloured, bloody, fseculent,
foetid, and discharged wjth
straining and tenesmus. Very
rarely '* rice-water *'.
Usually precedes vomiting.
Is watery or like whey.
** Rice-water", liquid, whitish
and discharged in an almost
continuous and involuntary
Peculiar, rough and whistling.
4. Madras Chemical Examiner^ Annual Report, 1929, p, 2.
5. G. St. George, Brit. Med. Jonr^ Feb. 5, 1921, p. 192."