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HYDROCYANIC ACID                                                       735

bullock. The fatal dose for a "bullock is about 20 grains oŁ pure hydrocyanic
acid. Very dilute acids and alkalies only retard the liberation of hydrocyanic
acid, but a normal acid or alkali stops it altogether. A strong solution of
an alkali (sodium carbonate) is, therefore, recommended as an antidote in
poisoning by the linseed plant.

Five buffaloes died after eating juar or young jonera plants, which yielded hydro-
cyanic acid on analysis.67 In Jodhpur, 95 cattle and 2 goats were affected by eating from
two bundles of juar kadvL Twenty-four of the cattle and the goats died. On examination
of the remnants of the two bundles of the kadvi hydrocyanic acid amounting to 0.0112 and
0.0073 per cent respectively was found.08 In Wasaliganj, Gaya, 21 cattle became ill after
eating the dry linseed plant and its dry fodder, Of these seven died.09

Hydrocyanic acid is rapidly absorbed from all mucous surfaces, and
even from the unabraded skin. Part of the acid thus absorbed is eliminated
unchanged by the lungs. It is, therefore, necessary to preserve for chemical
analysis one lung along with the other viscera which are usually preserved.
Another part is changed in the tissues to sulphocyanides, which are excreted
in the urine. It is also partially eliminated by the skin.

The toxic action of potassium cyanide depends largely upon the hydro-
chloric acid contents of the stomach. It is said that Rasputin was given a
large amount of potassium cyanide in pastries, but he did not suffer from
any ill-effects as owing to alcoholic gastritis the liberation of hydrocyanic
acid was inhibited by the lack of free hydrochloric acid in the stomach, and
absorption was hindered by the thickening of the gastric mucous mem-
brane.70 In this connection it may be mentioned that harmless carbonate
may be formed by the action of atmospheric carbon dioxide and moisture
on potassium cyanide, if it is kept for a sufficiently long time. An old sample
of potassium cyanide may also be converted by hydrolysis into a compara-
tively harmless salt, potassium formate. In his annual report for the year
1939, Bagchi, Chemical Examiner, Bengal, reports the case of a man, who
took a heavy dose of cyanide in mistake for sodium bicarbonate, but he was
saved from the inevitable fate, as the cyanide which he took was in all
probability a very old sample, and was, therefore, mostly converted into
formate, The stomach wash was found to contain traces of hydrocyanic
and formic acids.

The double cyanides, such as potassium ferrocyanide and potassium
ferricyanide, are practically non-toxic, but they give off hydrocyanic acid
in certain conditions and act as poisons. Thus, potassium ferrocyanide may
produce poisonous symptoms and cause death, when it is taken in association
with acids. A case is recorded, where death occurred after a dose of potas-
sium ferrocyanide and then one of tartaric acid. Another instance is also
recorded of the death of a man who took potassium ferrocyanide along with
a mixture of equal parts of nitric and hydrochloric acids,71 In his annual
report for the year 1936, the Chemical Examiner, Bengal, cites the case of a
Mahomedan male, aged about 22 years, who committed suicide by taking
potassium ferrocyanide. On inspection of the body a big patch of submucous
haemorrhage was noticed in the cardiac end of the stomach.

67,   Beng. Chem. Exam. Ann. Eep., Ind Med. Ga2., Sep. 1910, p. 863.

68,   UP, Chem. Exam, Ann, Rep,, 1926, p, 4.

69,   Beng. Chem, Exam. Ann. Kep,, 1936, p. 16.

70,   Leschke, din. Toxic,, Eng. Transl. by Stewart and Dorrer, 1934, p. 145f

71,   Blyth, Poisons, Their Effects and Detection, Ed, V, p, 223,