Treatise on Poisons by Sir Robert Christison

CLASS SECOND. OF NARCOTIC POISONS GENERALLY. The term narcotism has been used by different writers with different significations, but is now generally understood to denote the effects of such poisons as bring on a state of the system like that caused by apoplexy, epilepsy, tetanus, and other disorders commonly called nervous. Narcotic poisons, therefore, are such as produce chiefly or solely symptoms of a disorder of the nervous system. The mode in which most narcotic poisons act has been well ascertained: they act on the brain or spine or both by entering the blood-vessels. Hence they are most active when most directly introduced into the blood, that is, when injected into the veins; and when they are applied to an entire membranous surface, their energy is in the ratio of its absorbing power. Thus, when injected into the chest, they act more rapidly than when swallowed. According to the generally received opinion, they are conveyed with the blood to the brain and spine on which they act. But, according to the views of Messrs. Morgan and Addison, they produce on the inner coats of the blood-vessels a peculiar impression, which is conveyed to the centre of the nervous system along the nerves. The usual symptoms in man and the higher order of animals are giddiness, headache, obscurity or deprivation of the sight, stupor or perfect insensibility, palsy of the voluntary muscles or convulsions of various kinds, and towards the close complete coma. The symptoms of each poison are pretty uniform, when the dose is the same. But each has its own peculiarities, either in the individual symptoms, or in the mode in which they are combined together. The morbid appearances they leave in the dead body are commonly insignificant. In the brain, where chiefly the physician is led from the symptoms to expect unnatural appearances, the organs are in general quite healthy. Sometimes, however, the veins are gorged with blood, and the ventricles and membranes contain serosity. The blood appears to be sometimes altered in nature; but the alteration is by no means invariable, and sometimes none is remarked at all. Many of the statements to be found in authors on the morbid appearances caused by narcotics are far from being accurate. Before proceeding to notice the genera of this class in their order, some remarks must be premised on the principal diseases which resemble them in the symptoms and morbid appearances. Of these the only diseases of much consequence are _apoplexy, epilepsy, inflammation of the brain, hypertrophy of the brain, inflammation of the spinal cord, and syncopal asphyxia_. _Of the Distinction between Apoplexy and Narcotic Poisoning._ _Of the Symptoms._—The symptoms of apoplexy are almost exactly the same as those of the narcotic poisons, namely, more or less complete abolition of sense and the power of motion, frequently combined with convulsions. This disease commonly arises from congestion or effusion of blood within the skull; but one variety of it, the nervous apoplexy of older authors, or simple apoplexy of the moderns, is believed to be an affection of the brain, unaccompanied by any recognizable derangement of structure. Apoplexy and narcotic poisoning may be often distinguished by the following criterions: