In the treatment of poisoning from nitre, if the patient has not vomited, ipecacuanha should be given till this effect is produced; warm diluent and demulcent drinks should be given, in any event, in order to dilute the salt, and to wash out the stomach; an opiate enema should be administered, or laudanum by the mouth; a sinapism applied over the epigastrium, and the patient's strength supported, if necessary, by wine or brandy diluted. There is no known antidote to nitre.

2. Mode Of Operating

Nitre in powder, or concentrated solution, is somewhat irritant to the stomach, and in large quantities often powerfully so; but there can, I think, be little doubt that its effects, whether remedial or toxicological, are produced mainly through its absorption. That it is absorbed, is shown not only by its disappearance from the stomach, but by its appearance in the urine, in which it has been repeatedly detected. it has also been found in the blood of a person to whom it was given in large doses. (Journ. de Pharm., x. 413.) its diuretic and diaphoretic action is explained by its stimulant influence upon the secretory function of the kidneys and skin, as it is carried through them with the blood. its purgative effect in large doses, with very free dilution, probably depends on a direct irritant action upon the intestinal mucous membrane. But the question as to the cause of its sedative influence over the circulation is not so easily settled. Does this depend upon an action directly on the heart, or first on the organic nervous centres and through them on the heart, or upon the blood, and through that both on the nervous system and the heart? in order to answer this question, we must ascertain how far nitre is known to affect the condition of the blood. it is asserted that, when added to freshly drawn blood out of the body, it impedes coagulation, and diminishes the adhesiveness of the red corpuscles, which it is said also to redden. Upon these points, the statements made are so positive that they cannot well be doubted. it is a very probable inference, that the same effects would, to a certain extent, result from the absorption of nitre into the circulation. The salt is indeed supposed, even in medicinal doses, to diminish the plasticity of the blood; and has been thought, if long continued, to bring on a depraved condition of that fluid, disposing to a typhoid state of the system. in cases of death from poisonous doses, it has been repeatedly noticed that the blood was liquid and uncoagulable. Statements generally agree on this point, though they differ as to the colour of the blood, which has sometimes been found black, in others redder than in health. Thus, M. Nonat, in a case of death from about an ounce, found the blood liquid and black (Briquet, Trait. Thérap. du Quinquin., etc.); while in another, referred to by Dr. Stevens, it was quite florid (Observ. on the Blood, p. 298); and, in the instance above mentioned as having been seen by Dr. Snowden, the lips were bright red. From the experiments of M. Briquet, it appears that nitre, injected into the veins of a dog, reduces immediately the force of the heart, as measured by the haemadynameter. (Traite, etc., ut supra, p. 111.) From six grains to half a drachm are said, when used in this way in dogs, to cause sudden death, as if by paralysis of the heart, preceded sometimes by convulsions. (Merat et De Lens, Dict., etc., v. 481.) From all these facts, it appears probable that nitre operates by immediately depreciating the character of the blood, and secondarily diminishing the powers and actions of the heart; though it is not impossible that it may exert a direct sedative influence on that organ. There is no proof that it has any direct action on the nervous centres. When given in small doses, it is absorbed, and moderately depresses the circulation, while it stimulates the skin or kidneys to throw it off. Larger doses irritate the mucous membrane, and, while partly absorbed, often operate on the bowels, and are in some measure discharged from the system. Still more largely given, if accompanied with a very large quantity of liquid, it is in like manner partly absorbed, and partly in general carried off by the bowels; but from its dilution it is but slightly irritant, and from the great bulk of liquid can be but slowly taken into the circulation, and not faster than it may be eliminated by the kidneys and skin; so that there is at no one time sufficient in the blood to produce serious effects. But in large quantities, as from half an ounce to an ounce and upwards, if swallowed in concentrated solution, it both irritates the stomach into inflammation, and, in its passage through the canal, is, from its small bulk, absorbed almost wholly, and thus entering the blood in larger quantities and greater concentration, exerts its full powers upon that liquid and upon the heart, poisoning the former, so as to give it the character of the blood in the most fatal malignant fevers.

3. Indications And Contraindications

Nitre would seem, from its known properties, to be called for in sthenic states of the system, with increased circulatory excitement and febrile heat, and especially when there is an excess of fibrin in the blood, or a disposition in inflammatory diseases to plastic exudation, or the formation of false membrane. it is contraindicated by general debility, an aplastic condition of the blood, as in low or typhoid states of system, and by inflammation of the stomach and bowels.

4. Therapeutic Application

The diseases in which nitre is employed as a sedative are the phlegmasiae, acute hemorrhages, and inflammatory fevers. it has also been used in scurvy.

1. inflammations. it may be used in any of the acute inflammations with a sthenic state of the system, except those of the stomach and bowels, and perhaps those of the kidneys and bladder, in which it may be supposed to act injuriously by its local stimulant properties, as it passes out with the urine. But the particular phlegmasiae in which it has been most highly recommended, and to which it would appear to be especially applicable from its peculiar influence on the blood, are pneumonia and acute rheumatism. in these it has generally been given combined with tartar emetic, or with this and calomel, in the form of the nitrous powders.