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.[1] 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.[2]
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.[3] 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.
In the dead body no particular alteration of structure was remarked. The heart, examined immediately after death from the introduction of the poison into the stomach, was found much gorged and motionless;
