Botanical name: 


Potassa, Potassium Hydrate, (Caustic Potash),—soluble in ½ of water and in 2 of alcohol; a painful and deeply-acting escharotic.
Liquor Potassae, Solution of Potassa,—Dose, ♏v-xxx, well diluted.
Potassii Acetas, Potassium Acetate,—very soluble in water and in alcohol. Dose, gr. v-ʒj. Diuretic and diaphoretic.
Potassii Citras, Potassium Citrate,—very soluble in water. Dose, gr. v-xxx, as diaphoretic and diuretic.
Potasii Bitartras, Potassium Bitartrate, (Cream of Tartar),—sol. in 102 of water. Dose, gr. xx-ʒj, as diuretic and refrigerant; ʒj-℥j, as purgative.
Potassii et Sodii Tartras, Rochelle Salt,—sol. in 1 ½ of water. Dose, ℥ss-j. Is a constituent of Effervescens Compositus.
Potassii Bicarbonas,—sol. in 3 ½ of water. Dose, gr. v-xxx.
Potassii Nitras, Potassium Nitrate, (Nitre),—sol. in 4 of water, insol. in alcohol. Dose, gr. ij-xx, well diluted, as diuretic and diaphoretic.
Potassii Chloras, Potassium Chlorate,—sol. in 17 of water. Dose, gr. v-xx. Explosive when mixed with organic matters (cork, sugar, tannic acid, etc.) or with oxidizable substances (sulphur, phosphorus, etc.) or when heated, triturated or concussed. It should never be mixed within glycerin in the presence of a free acid.
Potassii Bichromas, Potassium Bichromate, —Dose, gr. 1/10-j.

The Bromide is treated of under Bromides; the Permanganate under Manganese, page 57.

Physiological Action. Caustic Potash, like the other caustic alkalies, destroys the tissues by combining with their water, dissolving the albumen and saponifying the fats. The Potassium Salts increase the saliva, promote oxidation and the retrograde metamorphosis. In small doses on an empty stomach they promote the formation of acid gastric juice, by favoring the outward osmosis of its constituents from the blood; in large doses they act chemically in the stomach, neutralizing its free acids, and disordering digestion. The Bicarbonate, given on an empty stomach, enters the blood unchanged, meets the neutral phosphate of sodium, forming the acid phosphate, and making the urine more acid. On a full stomach it is decomposed before entering the blood, and makes the urine less acid. The Vegetable Acid Salts (Acetate, Citrate, etc.) enter the blood in their own form, are there decomposed, forming CO2 and alkaline carbonates, in which form they are excreted, alkalinizing the blood and urine. They are also diuretics, increasing both the water and the solids of the urine, but decreasing the uric acid by increasing oxidation. The Mineral Salts (Nitrate, Chlorate, etc.) are not decomposed in the blood, but are eliminated in their own form; the Nitrate being a most active diuretic, the Chlorate irritating the kidneys, and causing albuminuria. In large doses these salts decompose the red corpuscles of the blood, and paralyze the motor ganglia of the heart. All Potassium Salts, in large doses, are cardiac poisons, muscular paralyzers, poisonous to protoplasm, especially to nerve tissues, and destructive to the ozonizing function of the blood. This is especially true of the Bromide.

Poisoning by Caustic Alkalies is treated by the Vegetable Acids, as vinegar, lemon-juice; then Demulcents and Oils to protect the mucous membrane, and sustaining measures to support the vital powers.

Therapeutics. As Alkalies the Potassium salts are used in—
Acute Rheumatism,—the Bicarbonate and Nitrate, to saturate the blood, and make the urine alkaline; is effective treatment for sthenic patients.
Lithaemia,—the Acetate or Citrate, to promote oxidation. If the Bicarbonate is given, it should be during digestion, to render the urine less acid.
Acidity and Atonic Dyspepsia, the Bicarbonate, or Liquor Potassae with a bitter, in small doses before meals. If given after meals larger doses are required for temporary alleviation by neutralizing the food acids.
Mouth Affections, as ulcerative stomatitis, aphthae, nursing sore mouth, follicular pharyngitis,—the Chlorate locally, as detergent wash. This salt must be cautiously used internally, as it is a dangerous irritant to the kidneys.
Inflammations,—the Acetate, to promote the excretion of resulting products.
Cardiac Dropsy, if general—the Bitartrate in infusion of Juniper.
Acute Desquamative Nephritis,—the Bitartrate, but not in Juniper infusion.
Diphtheria,—the Chlorate both locally and internally, with the Tincture of the Chloride of Iron, has a high reputation. It should never be prescribed in a mixture with glycerin, lest an explosion result.
Skin Affections, as acne, eczema, prurigo, etc.,—alkaline solutions, locally.
Catarrhs, nasal, buccal, or vaginal,—the Bichromate (gr. j-x ad ℥iv aquae), locally ;—or the Chlorate as a detergent wash.

A Compend of Materia Medica, Therapeutics, and Prescription Writing, 1902, by Sam'l O. L. Potter, M.D., M.R.C.P.L.