failure of internal tissue respiration brought on by a change of the blood
due to the formation of cyanmethaemoglobin, which yields a spectrum
resembling that of reduced haemoglobin, i.e. a thick band between the lines
D and E.
When a small poisonous dose is taken, the patient experiences a hot,
bitter taste and constriction of the throat and complains of salivation, giddi-
ness, nausea, headache, confusion of ideas, sense of oppression in the chest,
loss of muscular power and insensibility. The face is suffused or bloated,
and the mouth is covered with froth, the eyes are glassy and prominent with
dilated pupils; the finger-nails are blue or purple. Convulsions of a tetanic
character and involuntary evacuations precede death. Vomiting is oc-
casionally observed and is sometimes the beginning of recovery.
The spasmodic or piercing cry, which is commonly observed in cattle
poisoning, is rarely met with in human poisoning.
Inhalation of the vapours of hydrocyanic acid produces a sense of con-
striction about the throat and chest, dizziness, vertigo, insensibility and death
from respiratory failure.
which is strongly alkaline
and frequently contains
potassium carbonate as
an impurity has a corro-
sive effect on the mouth,
throat and stomach and
causes epigastric pain and
vomiting. The other
symptoms are cyanosis
of the face, neck and
hands, white froth about
the lips, dilated pupils,
imperceptible pulse, slow
and shallow respirations,
incontinence of urine,
coma and death. Some-
times, convulsions may
precede death. Williams 54
reports non-fatal cases of
acute and severe gastro-
enteritis in hotels from
cyanide poisoning appar-
ently from silver polish
containing sodium cya-
nide to the extent of 20.54
Chronic poisoning oc-
curs among photograph-
ers, gilders and workmen
who are constantly en-
gaged in preparing or
handling either hydro-
cyanic acid or potassium
cyanide. The symptoms
are headache, vertigo,
loss of appetite, nausea, constipation, foetid breath, dyspnoea and ansemia.
Fig. 199.—Potassium Cyanide Poisoning: Staining over
the upper lip and left side of face due to the corrosive
action of the poison.
(From a photograph lent kindly ly Dr. H, S. Mehta.)
54. Jour. Arner. Med. Assoc., March 1, 1930, p. 627.