however, seems to have found it more active in the form of sulpho-cyanate of potassa. Two scruples in an ounce of water produced in a dog spasmodic breathing, convulsions, efforts to vomit, and death in seven minutes; and forty grains killed another in less than two hours. In the latter animal he detected the poison by the sulphate of iron in the blood, lungs, liver, spleen and kidneys.[1] Some experiments by Soemering would even make it out to be a poison of very great energy; for half a drachm of concentrated sulpho-cyanic acid given to a dog occasioned immediate death; and the same quantity of sulpho-cyanate of potassa killed another in one minute.[2]
Cyanic and cyanous acids are not poisonous, according to the experiments of Hünefield;[3] but cyanogen is a powerful poison, as will be mentioned under the head of the Narcotic Gases.
The symptoms of hydrocyanic acid observed in man are very similar to those witnessed in animals.
Coullon has given a good account of the effects of small doses as ascertained by experiment on himself. When he took from 20 to 86 drops of a diluted acid, he was attacked for a few minutes with nausea, salivation, hurried pulse, weight and pain in the head, succeeded by a feeling of anxiety, which lasted about six hours.[4] Such symptoms are apt to be induced by too large medicinal doses. Another remarkable symptom which has been sometimes observed during its medicinal use is salivation with ulceration of the mouth. Dr. Macleod thrice had occasion to remark this in patients who had been using the drug for about a fortnight, and twice in one individual; and Dr. Granville says he had also twice witnessed the same effect.[5]
As to the effects of fatal doses, it is probable that in man, as in animals, two varieties exist. When the dose is very large, death will in general take place suddenly, without convulsions. But for obvious reasons the symptoms in such cases have not been hitherto witnessed.
The most complete account of the symptoms from fatal doses when convulsions occur, is given in a case reported by Hufeland of a man, who, when apprehended for theft, swallowed an ounce of alcoholized acid, containing about forty grains of the pure acid. He was observed immediately to stagger a few steps, and then to sink down without a groan, apparently lifeless. A physician, who instantly saw him, found the pulse gone and the breathing for some time imperceptible. After a short interval he made so forcible an expiration that the ribs seemed drawn almost to the spine. The legs and arms then became cold, the eyes prominent, glistening, and quite insensible; and after one or two more convulsive expirations he died, five minutes after swallowing the poison.
In Horn's Journal is recorded another case which also proved fatal
