Prussic Acid (Accident or Negligence).
Ages,0-11-55-1515-2525-6565 and
above		Total
Males,...11112116
Females,11...27...11
Totals,121319127
Cyanide of Potassium (Accident or Negligence).
Ages, 1-55-1515-2525-6565 and
above		Total
Males, 1141...7
Females, 1......3...4
Totals, 2144...11
Prussic Acid (Suicide).
Ages, 15-2525-6565 and
above		Total
Males, 2315623202
Females, 513119
Totals, 2816924221
Potassium Cyanide (Suicide).
Ages, 5-1515-2525-6565 and
above		Total
Males, 16885100
Females, ...615122
Totals, 1121036122

To these figures must be added 10 cases of murder (2 males and 8 females) by prussic acid, and 4 cases of murder (3 males and 1 female) by potassic cyanide.

In order to ascertain the proportion in which the various forms of commercial cyanides cause death, and also the proportion of accidental, suicidal, and criminal deaths from the same cause, Falck collated twelve years of statistics from medical literature with the following result:—

In 51 cases of cyanide poisoning, 29 were caused by potassic cyanide, 9 by hydric cyanide, 5 by oil of bitter almonds, 3 by peach stones (these 3 were children, and are classed as “domestic,” that is, taking the kernels as a food), 3 by bitter almonds (1 of the 3 suicidal and followed by death, the other 2 “domestic”), 1 by tartaric acid and potassic cyanide (a suicidal case, an apothecary), and 1 by ferro-cyanide of potassium and tartaric acid. Of the 43 cases first mentioned, 21 were suicidal, 7 criminal, 8 domestic, and 7 medicinal; the 43 patients were 24 men, 14 children, and 5 women.

The cyanides are very rarely used for the purpose of murder: a poison which has a strong smell and a perceptible taste, and which also kills with a rapidity only equalled by deadly bullet or knife-wounds, betrays its presence with too many circumstances of a tragic character to find favour in the dark and secret schemes of those who desire to take life by poison. In 793 poisoning cases of a criminal character in France, 4 only were by the cyanides.

Hydric and potassic cyanides were once the favourite means of self-destruction employed by suicidal photographers, chemists, scientific medical men, and others in positions where such means are always at hand; but, of late years, the popular knowledge of poisons has increased, and self-poisoning by the cyanides scarcely belongs to a particular class. A fair proportion of the deaths are also due to accident or unfortunate mistakes, and a still smaller number to the immoderate or improper use of cyanide-containing vegetable products.

§ 256. Accidental and Criminal Poisoning by Prussic Acid.—The poison is almost always taken by the mouth into the stomach, but occasionally in other ways—such, for example, as in the case of the illustrious chemist, Scheele, who died from inhalation of the vapour of the acid which he himself discovered, owing to the breaking of a flask. There is also the case related by Tardieu, in which cyanide of potassium was introduced under the nails; and that mentioned by Carrière,[240] in which a woman gave herself, with suicidal intent, an enema containing cyanide of potassium. It has been shown by experiments, in which every care was taken to render it impossible for the fumes to be inhaled, that hydrocyanic acid applied to the eye of warm-blooded animals may destroy life in a few minutes.[241]

[240] “Empoisonnement par le cyanure de potassium,—guérison,” Bullet. général de Thérap., 1869, No. 30.

[241] N. Gréhant, Compt. rend. Soc. Biol. [9], xi. 64, 65.