POTASSIUM
Nitrate of Potash
This substance is well known as nitre, saltpetre, and sal prunella. In large doses it acts as an irritant, and cases are recorded in which it has been used to poison children. In one case, the presence of crystals of the salt in some of the dried vomited matter on the child‘s shoe, led to an explanation of the cause of death.
Symptoms.—Those of a pure irritant, to which death must be referred, and not to any constitutional action of the drug. The nervous symptoms, which are sometimes very marked, are, as is well known, common to the action of many pure irritants. In some cases there is suppression of urine.
Post-mortem Appearances.—Those produced by irritants generally.
Chemical Analysis.—Separate the poison by dialysis, evaporate, and test the crystals as directed under nitric acid.
Fatal Dose.—About an ounce.
Fatal Period.—Two hours.
Treatment.—The same as for other irritants; demulcent drinks. Promote vomiting.
Sulphate of Potash
Sal Polychrist, Sal de Duobus, or sulphate of potash, acts as an irritant poison, being largely used in France as an abortive. The symptoms and the post-mortem appearances are much the same as those produced by the nitrate. A like treatment may also be adopted. In the detection of this substance, the nitrate of baryta will point to the acid present, and bichloride of platinum to the presence of potash.
Chlorate of Potash
This salt acts as a poison when taken in large doses, producing symptoms which might be mistaken for poisoning with arseniuretted hydrogen, or for such diseases as hæmoglobinuric fever.
Symptoms.—These comprise pain in the stomach and bowels with vomiting, collapse and stupor, cyanosis, jaundice; diminution of the urine, which contains hæmoglobin, casts, and albumen. It is a question whether the jaundice is hæmatogenous or hepatogenous. Chlorate of potash destroys the red corpuscles, the hæmoglobin is dissolved out and is set free in the liquor sanguinis.
Fatal Dose.—45-50 grains proved fatal to a child three years old. For an adult 390 grains to an ounce and a half.
Fatal Period.—From five hours to several days.
Treatment.—The stomach should be washed out through the syphon tube. Venæsection may be useful, with subsequent transfusion of fresh blood. The nephritis and other symptoms must be treated generally.
Post-mortem Appearances.—The mucous membrane of the stomach may be inflamed and submucous hæmorrhages may be found. The blood is chocolate in colour and gives the spectrum of methæmoglobin. The spleen is enlarged and chocolate-coloured, and the kidneys acutely inflamed.
Chemical Analysis.—Chlorate of potash may be separated from organic material by dialysis.
1. If to a solution of the salt a few drops of indigo sulphate be added, and then a few drops of strong sulphuric acid, the indigo-blue is bleached.
2. If a small crystal of the chlorate be heated in a test tube with a drop of strong sulphuric acid, it explodes with detonation.