thirty-two stairs. He stood in the middle of the room, moved his hand impatiently, and said: "Be quick-give me something." He drank some solution of ammonia and tincture of sesquichlorid of iron and tried to excite vomiting by putting his finger into his throat. After one or two abortive attempts at vomiting he fell suddenly, completely insensible. He died, without convulsions, in about ten minutes. "In a few hours after death the face regained its natural expression and color, and it was noticed that it had the hue of health, and perfectly resembled that of one asleep; but after the lapse of a few more hours it again became congested, red, puffed, and ecchymosed," and a little later face, scalp, neck, shoulders, and thighs were mottled deep red. About 3.5 grains (0.22 gm.) of anhydrous acid had been taken.1 OIL OF BITTER ALMONDS. When bitter almonds are expressed, they yield a bland, fixed oil (Oleum Amygdala Expressum, U. S. P.). When the residuary cake is submitted to distillation with water, the volatile Oleum Amygdalæ Amara (U. S. P.) is obtained. The latter is composed largely of benzaldehyd, and to a much less extent of hydrocyanic acid. These bodies are derived from the action, in the presence of water, of a ferment, emulsin, upon a glucosid, amygdalin, contained in the almonds. This action is represented by the following equation: + CHNO - 2H2O = 20H12O6+ CH5.CHO+HCN. The benzaldehyd and hydrocyanic acid are volatile, and are, therefore, contained in the distillate. The ordinary crude oil of bitter almonds, which is official, contains from 2 to 14 per cent. of hydroevanic acid. It was formerly much used as a flavoring agent in confectionery, etc.; at present benzaldehyd or the "synthetic oil of bitter almonds," which contains no hydrocyanic acid, is said to be largely used instead of the natural oil. The "essence of bitter almonds " is a solution of the oil in alcohol. Some pomades and salves contain oil of bitter almonds, and their use may lead to poisoning. Of 402 cases of cyanic poisoning collected by Witthaus, 61 were due to the oil of bitter almonds; some of these were suicidal, others were accidental,3 while in some cases the poison is alleged to have been used for criminal purposes. 4 The poisonous action of the oil of bitter almonds is due entirely to the hydrocyanic acid contained in it, and the symptoms are the same as those described above. In some cases, however, the effects are more slowly produced, although death may occur in ten minutes. The amount of hydrocyanic acid contained in the various specimens of the oil of bitter almonds varies considerably, so that it is impossible to state with accuracy the fatal dose; it is probable, however, that 10 drops of 1 Hickman, Lancet, 1866, vol. i., p. 310. 2 The synthetic oil of bitter almonds must be carefully distinguished from the "artificial oil of bitter almonds"; the latter is nitrobenzene and is very poisonous. Allen (Internat. Med. Mag., 1893, vol. ii., p. 126) described a case of poisoning by * oil of bitter almonds "; the intense and long-continued cyanosis and the "tar '-like character of the blood strongly suggest nitrobenzene. 3 Pharm. Jour, and Trans., 1883, 3., vol. xiii., pt. ii., pp. 579, 619; 1883, 3 s., vol. xiv., pt. i., p. 58. Lancet, 1858, vol. i., p. 128. many preparations would be fatal. Taylor records a case in which a woman died in half an hour from 17 drops; in another case a man died in ten minutes from 2 drams (7.5 c.c.). On the other hand, with prompt treatment, patients have recovered from 6 drams (22.5 c.c.). A child of three died in about two hours and a half after taking about 20 drops of the "essence of bitter almonds";' this should correspond to from 2 to 5 minims of the essential oil, but the preparations vary much in strength. Bitter Almonds.-Poisoning by eating bitter almonds themselves is comparatively rare, but a few fatal cases are on record. Bitter almonds contain about 3 per cent. of amygdalin. Since 100 parts of amygdalin yield 5.9 per cent. of hydrocyanic acid, somewhat more than 1 ounce (31 gm.) of the almonds would be required to yield 1 grain (0.064 gm.) of anhydrous hydrocyanic acid. Bitter almonds weigh on the average about 11 grains (0.7 gm.) each; hence death may be expected to follow the eating, by an adult, of about 50 almonds. Very severe symptoms were produced in a child by eating 10 bitter almonds. In a case reported by von Maschka3 about 2 ounces (77.5 gm.) were taken with suicidal intent. The symptoms began in a few minutes; there were unconsciousness and convulsions in ten minutes and death in an hour and a half after the appearance of the first symptoms. Baker reports a case in which a man stated that he had eaten "two handfuls" of bitter almonds; the symptoms did not appear for some time, but were then very severe. Recovery followed. 4 Many other plants contain amygdalin, from which hydrocyanic acid may be evolved. A few cases of severe, and even fatal, poisoning, especially in children, are reported from the eating of the kernels of the peach, the fruit of the common wild black cherry (Prunus serotina), the kernels of the common cherry and of the apple. The symptoms are due entirely to the hydrocyanic acid, and are those already described. The course of the poisoning, however, is usually slow. Thus a girl of five did not die for seventy hours after eating an unknown quantity of cherry-kernels. The bark and leaves also of many plants belonging to the plum family contain hydrocyanic acid in combination. The fact that hydrocyanic acid is so widely distributed in nature has been used by the defense in criminal cases as an argument that the hydrocyanic acid found by the prosecution came from substances that had been eaten. Hence it is important to know, even approximately, the quantity of hydrocyanic acid that can be obtained from various fruits and seeds. According to Blyth, the kernels of the peach contain about 2.85 per cent. of amygdalin (== 0.17 per cent. HCN); those of the plum, 0.96 per cent. (= 0.056 per cent. HCN); those of the cherry, about 3 per cent. ( about 0.37 per cent. HCN); and apple-pips, 0.6 per cent. (= 0.035 per cent. HCN). 1 Armstrong, Austral. Med. Jour., 1880, vol. ii., p. 202. 2 Horrocks, Austral. Med. Gaz., 1898, vol. xvii., p. 252. 3 See Blyth, Poisons, 1895, p. 209. Baker, Brit. Med. Jour., 1881, vol. ii., p. 12. Cyanids other than Hydrogen and Potassium Cyanids. -All cyanids that are soluble in water or from which hydrocyanic acid is liberated by the action of weak acids are poisonous. Among such bodies may be mentioned the cyanids of sodium, ammonium, zine, silver, and mercury. In cases of poisoning by mercuric cyanid the pathologic action of both mercury and hydrocyanic acid are noticed. The double cyanids, such as potassium ferrocyanid, Prussian blue, Turnbull's blue, etc., are usually considered to be non-poisonous, but under some conditions hydrocyanic acid is split off and poisonous symptoms are produced.' Thus when potassium ferrocyanid is taken simultaneously with acids, fatal poisoning may occur. Cyanic acid, the cyanates, and the sulphocyanates are nearly harmless. Cyanogen, cyanogen iodid, cyanogen chlorid, and methyl cyanid are all very poisonous. 3 Isolation. There have been undoubted cases of poisoning with hydrocyanic acid where competent chemists were unable to detect the substance a few hours after its use. On the other hand, Dragendorff 2 was successful in showing the presence of the poison in the stomach of a dog four weeks after the administration of potassium cyanid and in a human corpse eight days after death, while Struve's recovery of hydrocyanic acid from a mixture of potassium cyanid and organic matter that had been preserved in a closed vessel for five hundred and forty-seven days shows that a chemical examination should never be omitted where circumstances point to the use of the poison. Bischoff'5 advises the analysis of the stomach, duodenum, blood, and organs rich in blood. 6 The separation of hydrocyanic acid from an acidified mixture of potassium cyanid and organic matter by distillation can offer no serious difficulty, but in case mercury is present, hydrocyanic acid will not be found in the distillate. On the other hand, the presence of hydrocyanic acid in the distillate may be attributed to non-poisonous potassium ferrocyanid, potassium ferricyanid, or potassium sulphocyanate, all of which yield hydrocvanic acid under the conditions stated. Before proceeding with the distillation, therefore, a portion of the material is filtered or dialyzed, and the liquid is tested with an acidified mixture of ferrous sulphate and ferric chlorid. A blue color indicates either potassium ferrocyanid or potassium ferricyanid, and a red color, potassium sulphocyanate. The result of this test, taken in connection with an analysis for mercury, will determine the course of the subsequent procedure. In the absence of mercury and compound cyanids the material under examination is thoroughly macerated with water and the mixture acidified markedly with tartaric acid, and submitted to a slow distillation 1 See Huber, Zeitschr. f. klin. Med., 1888, vol. xiv., p. 515 (poisoning by Prussian blue; recovery). Ermittelung von Giften, Göttingen, 1895, p. 70. 3 Zeitschr. f. anal. Chem., vol. xii., p. 14. Sokoloff, Ber. d. d. chem. Ges., vol. ix., p. 1023. 5 Ibid., vol. xvi., 1351. p. 6 Struve, loc. cit. |