The plants already enumerated are sufficient to illustrate the symptoms and physiological action of the acrid poisons of the vegetable kingdom. We shall, therefore, conclude the history of this class with some account of the nitrate of potass, which has been ranked both by Fodéré and Orfila under this division of their classification.
Nitre. Nitrate of Potass.
The sensible qualities of this salt are too well known to require any description. It generally occurs crystallized in six-sided prisms, terminated by dihedral summits. It is composed of one proportional of nitric acid, and one proportional of potass. It dissolves in seven parts of water at 60°, and in its own weight at 212° Fah. Its solution is attended with a great reduction of temperature. It is permanent in the air, melts when exposed to a moderate heat; and, when cast into moulds, constitutes what is known in commerce by the name of sal prunelle. When mixed with inflammable matter it undergoes, in a strong heat, a rapid species of combustion, which, in chemical language, is termed deflagration. Concentrated sulphuric acid, when poured upon this salt in powder, decomposes it at the ordinary temperature, and disengages vapours of nitric acid, which are white, and not very abundant.
Symptoms of poisoning by Nitre.
This salt, when taken in a large dose, acts violently on the stomach and bowels, and occasions syncope and death. There are several cases recorded of its having been taken by mistake for Glauber’s salt.
On these occasions, the patients have been seized with violent vomiting and purging of blood, attended with severe pains in the bowels, and a sense of burning heat, referred to the chest and stomach; cold extremities, fluttering pulse, laborious breathing, syncope, and death. The above effects have been produced by an ounce and a half of nitre; although, as Dr. Gordon Smith has observed, the same quantity of this salt has been inadvertently swallowed without the production of such tremendous consequences.
From the experiments of Orfila, it appears that if this salt be inserted into a wound, it occasions a fatal gangrene. Its action is undoubtedly the effect of its acrid nature, destroying the vitality of the textures with which it comes in contact. It is not absorbed.
Organic lesions discovered by dissection.
In those recorded cases of death from the ingestion of nitre, the stomach has been found red, scattered over with blackish spots, and its mucous membrane disorganized.