Of the Peach, Cluster-Cherry, Mountain-Ash, &c.
Little need be said of the other plants formerly mentioned among those which yield hydrocyanic acid, and act on the system in consequence of containing that substance.
The Amygdalus persica or peach is the most active of them. Most parts of the plant exhale the odour of the bitter-almond, but particularly the flowers and kernels. According to the chemical researches of M. Gauthier, the fresh young shoots of the peach collected in July contain, weight for weight, even more essential oil than the bitter almond, or cherry-laurel leaves; for 250 grains yielded nearly five grains of it or two per cent.; and he found the oil may be easily procured by distilling the shoots without addition till the product begins to pass over clear.[[1988]] The kernels of the peach, when distilled with water, yield nearly one grain of hydrocyanic acid per ounce.[[1989]]
Coullon has collected two instances of poisoning with the peach-blossom. One is the case of an elderly gentleman, who swallowed a sallad of the flower to purge himself. Soon afterwards he was seized with giddiness, violent purging, convulsions, and stupor; and he died in three days. Here the poison must have proved fatal by inducing true apoplexy in a predisposed habit; at least poisoning with hydrocyanic acid never lasts nearly so long. The other, a child eighteen months old, after taking a decoction of the flowers to destroy worms, perished with frightful convulsions, efforts to vomit, and bloody diarrhœa.[[1990]] The peach-blossom would therefore appear to be rather a narcotico-acrid, than a narcotic.—Peach-leaves are represented to have produced even purely irritant effects. A man, who took a decoction of a handful boiled in a quart of water down to a third,—when of course no hydrocyanic acid could remain,—was attacked with tightness in the chest, a sense of suffocation, violent colic, pain in the stomach and frequent desire to vomit, followed by a hard pulse, restlessness, and flushing of the face. But he recovered slowly under the use of fomentations and opiates.[[1991]]
The bark of the Prunus padus, or cluster-cherry, a native of this country, owes its poisonous qualities to the same substance as the preceding plants. Heumann found that the distilled water obtained from two ounces of bark in March contains two grains of acid, two ounces of developed leaves half a grain, and two ounces of the seed a trifle less.[[1992]] Its distilled water has the odour of bitter almonds, contains the same essential oil with that of the bitter almond, and yields more hydrocyanic acid than the cherry-laurel water.[[1993]] The oil, according to Schrader, contains 9·25[[1994]] per cent. of hydrocyanic acid, according to Göppert only 5·5 per cent.[[1995]] Bremer, who has examined this plant with great care, found that both the distilled water and the essential oil kill mice when put into the mouth, eye, nose, ear, anus, or a wound; and that half an ounce of the water killed a dog in twelve minutes.[[1996]] The fruit is also poisonous. It has a nauseous taste, but communicates a pleasant flavour to spirituous liquors. The kernels yield by expression a transparent, fixed oil, concrete at 41° F., which contains a small quantity of the essential oil; and the cake which is left yields so much of the latter, that, as we are informed by M. Chancel of Briançon, a handful has proved fatal to cows in a short time.[[1997]] In these kernels, as in the bitter almond, the essential oil does not exist ready formed, but is developed only in consequence of the contact of water; and hence, if the fixed oil by expression contains a little of it, as Chancel says, this must arise from the kernels having been moist when squeezed.
The Sorbus aucuparia, mountain-ash, or Rowan-tree as it is called in Scotland, has been lately added to the list of plants which abound in the same poisonous principle. M. Grassmann of St Petersburgh has found that many parts of this tree, such as the flowers and the bark of the trunk and branches, contain more or less of the peculiar essential oil; and that the root in particular contains so much in the month of May as to smell strongly of it when broken across, and to yield a distilled water which holds fully as much hydrocyanic acid as that procured from an equal weight of cherry-laurel leaves.[[1998]]
Several other plants of the same natural order possess similar though weaker properties, such as the Prunus avium, or black-cherry, or mazzard, the Prunus insititia, or bullace, the Prunus spinosa, or sloe, the Amygdalus nana, or dwarf-almond, and even the leaves and kernels of the common cherry, the Cerasus communis. Twelve ounces of cherry kernels distilled with water, yield, according to Geiseler, seven grains of hydrocyanic acid.[[1999]] I have no doubt, from my experiments, that the seeds of Pyrus malus, the apple, Pyrus aria, the white-beam, and also, if the taste may be taken for a criterion, the whole seeds of the Pomaceæ, yield by distillation with water a large quantity of hydrocyanic acid.
CHAPTER XXX.
OF POISONING WITH CARBAZOTIC ACID.
A substance long known to chemists by the name of indigo-bitter, which is procured by the action of nitric acid on indigo, silk, and other azotized substances, and which has been found to consist chiefly of a peculiar acid, termed by Liebig, from its composition, the carbazotic acid, appears to be a pure narcotic poison of considerable activity.[[2000]] It is in the form of shining crystals, of an excessively bitter taste, and of a yellow colour so singularly intense that it imparts a perceptible tint to a million parts of water. The pure crystals are composed of carbon, azote, and oxygen.
The only account I have seen of the physiological properties of this substance is a full analysis by Buchner in his Toxicology, of some interesting experiments by Professor Rapp of Tübingen.[[2001]] He found that sixteen grains in solution, when introduced into the stomach, killed a fox, ten grains a dog, and five grains a rabbit, in an hour and a half; that the injection of a watery solution into the windpipe occasioned death in a few minutes; that the introduction of it into the cavity of the pleura or peritonæum occasioned death in several hours; that a watery solution of ten grains injected into the jugular vein of a fox killed it instantaneously, and in like manner five grains affected a dog in three minutes and killed it in twenty-four hours; and that thirty grains applied to a wound killed a rabbit. The symptoms remarked from its introduction into the stomach of the fox were in half an hour tremors, grinding of the teeth, constant contortion of the eyes and convulsions, in an hour complete insensibility, and death in half an hour more. In the dog there was also remarked an attack of vomiting and feebleness of the pulse.