POISONING - The class is an inconvenient one, so far as .the principles of diagnosis are eoncerned, because the symptoms may be general or they may be qnite local ; they may be rapid in their access, or very slow in their progress ; they may be almost entirely independent of the peculiar nature of the poison, or they may be specific, just as they consist of vital actions set up by the presence of a foreign body or of special perversions of function or nutrition which are in duced by it. Their only point in common is the history, when such can be obtainM, of a poison actually received into the body. When this is known, and the symptoms follow in the succession in which experience has taught that they ought to do, the diagnosis is complete.
The class is also imperfect in a scientific point of view, because one at least (syphilis) has a tendency to increase by a process of development after its admission. It thus might, perhaps, be more justly ranged along with the symotic poisons, were it not that it is clearly separated from them by the ab sence of febrile disturbance, and the necessity for actual contact in order to its introduction. The vegetable and mineral poisons have no such power : if life be not destroyed, and the source from whence they are derived be cut off, in course of time they will be eliminated.
§ 1. Poisons; properly so called.—It is not the purpose of this work to enter on the field of medical jurisprudence; and there fore we must content ourselves with a general outline of the points which may serve to discriminate a case of sudden illness from one of ordinary poisoning.
Much may be learned regarding the nature of the attack, inde pendently of ascertaining the fact that poison has been taken, by a careful inquiry into the antecedent circumstances. Among them stands, first, the suddenness of the seizure. We are led to inquire if there have been any premonitory symptoms—any ailment prior to its occurrence; how the patient was last engaged whether he had taken food, drink, or medicine; who was in his company, Svc.: and, in order to be prepared to give evidence, if called upon, it is wise to mark every circumstance about the patient, anything remarkable in the room, among the attendants,• and to be careful that nothing be thrown away. The order of the pheno mena is to be noted, so far as we can collect it from the statements of others, or from our own observation.
His general condition next occupies our attention; the absence of fever; a condition of collapse or depression; of sickness or vomiting ; of pain ; of excitement or delirium ; of tetanic spasm or convulsion; • of unconsciousness, insensibility, or coma. These must be contrasted with similar conditions arising out of various diseases, in order to ascertain whether any sudden internal lesion could have caused the group of symptoms presented. It is scarcely necessary to remark, that those diseases (e. g. cholera) which in the suddenness and intensity of their attack resemble cases of ordinary poisoning, may often be discriminated by their epidemic character. A few special indications of the more important classes of poisons may be here pointed out, in order to guide the student in his investigation of cases of this nature.
a. Irritant poisons prodlice irritation of the mouth, throat, and stomach. This may amount to actual corrosion, or consist merely in a burning sensation on the tongue and constriction in the throat; perhaps it may affect the larynx, causing hoarseness ; or there may be acute pain in the stomach, which is afterwards asso ciated with tenderness to the touch. The latter is usually dis tinguished from peritonitis following on rupture of the stomach by its much more local character and its lower degree of inten sity ; except, perhaps, when a corrosive poison has been taken, and then the indications in the mouth and throat are conclusive. Rupture of the stomach most commonly follows upon a long train of dyspeptic symptoms indicating ulceration, or a violent blow after repletion. Vomiting and diarrhcea are usually the concomi tants of irritant poisoning, and rarely of rupture, except when a fit of vomiting is its cause. In both cases, extreme collapse is very often present, and then the pain is a less prominent symptom; but in those which are caused by poisons, we shall probably find other phenomena belonging to the nervous system; such as giddi ness, dazzling of the eyes, tinnitus aurium, spasms, cramps, con vulsions, Stc., because their effects are not due simply to corrosion, but are produced by their specific action on the cerebrospinal system, as well as that which they exert upon the nerves and mucous membrane of the stomach.