MINERAL POISONS.
These are generally considered as corrosive poisons, as they inflame and destroy the parts to which they are ap plied. Their power varies much, according to the dose,— to their solid or liquid state,—or to their internal or exter nal application. They are amongst the most active and dangerous.
In a physiological view, their effects on the system vary exceedingly. Sometimes they act as stimulants to the brain and nervous system, and at others their efforts ap pear to be of a sedative nature. In some cases they aug ment the natural secretions, in others they interrupt them. Hence it is that, in safe hands, they become medicines of great efficacy. When in very strong doses, they produce speedy death, the immediate cause of which is not always the same. Sometimes the poison is absorbed, and acts on the brain, the heart, and other organs. Sometimes the primary action on the stomach is communicated by sym pathy to these, without any apparent absorption ; and, in other cases, death seems to be the consequence of their immediate operation on the stomach.
Symptoms produced by these common ones are burning heat in the mouth, cesophagus, stomach, and intestines, with thirst; pains through the whole ali mentary canal, and chiefly in the stomach and oesophagus; hiccup, nausea. painful and obstinate vomit ings, sometimes bloody, with tenesmus and bloody excretions ; the pulse small, frequent, and often imperceptible; coldness some times, at others violent heat ; dysuria, strangury, and cold sweats. Sometimes petechix, and at others miliary erup
tions, break out. Delirium, blindness, convulsions, or loss of the intellectual faculties, complete the horrible cata logue.
Anatomical of the alimentary ca nal, strictures, gangrene, or sphacelus, and corrosions, are the most obvious appearances on dissection. Sometimes the skin is affected with gangrenous spots; or the white skin for a large space has been found black. The lungs have also been found in a state of gangrene from arsenic. In some cases, however, death occurs, and yet no obvious injuries can be discovered.
Medical Treatment. In some cases, antidotes may be administered on just chemical principles, as we shall men tion in treating of the different substances. Of ancient, and often inefficacious or imaginary antidotes, the cata logue is immense ; as few objects have engaged the atten tion of physicians more, in the dark ages of medicine. Evacuants, and the antiphlogistic systems; are einployed in our own days on more rational principles. These are subject to no errors in the hands of ignorance, as antidotes often are ; since the proposed decomposition may be im possible, or the treatment as injurious as the poison.
For the chemical history of (lit following substances we must refer to our article CHEMISTRY.