POTASSIUM 103 



the corresponding salts of potassium and are preferable as medicinal 

 agents to the latter. 



Blood. — When given for any considerable' period, the potassium, like 

 the sodium salts, impoverish the system and produce a more fluid state of 

 the blood. Large doses of the potassium salts are likely to occasion 

 purging, while small doses are apt to cause diuresis. The carbonates and 

 vegetable salts resemble each other in action, but that of the mineral salts 

 is peculiar to the individual compound. 



PoTAssii Hydroxidum. Potasslum Hydroxide. KOH. (U. S. P.) 

 Synonymg.—Potassa. caustica, B. P.; potash, potassium hydrate, caustic pot- 

 ,ash, lapis causticus chirurgorum, E.; potasse caustique, Fr.; aetz kali, G.; kali 

 causticum fusum, P. G. 



Derivation. — A solution of potassium hydrate is evaporated; the residue is 

 fused and run into moulds. 



Properties. — Dry, white, or nearly white, fused masses, or sticks, hard and 

 brittle, showing a crystalline fracture; odorless, and of a very acid and caustic 

 taste. Exposed to the air, it very rapidly absorbs carbon dioxide and moisture, 

 and deliquesces. 1 Gm. dissolves in 0.9 mils of water, about 3 mils of alcohol, 

 in 2.5 mils of glycerin at 25°* C. (77° F.), also in 0.6 mil of boiling water; very 

 soluble in boiling alcohol. 



Liquor Potassii Hydkoxidi. Solution of Potassium Hydroxide. (U. S. P.) 



An aqueous solution of potassium hydroxide (KOH), containing not less than 

 4.5 per cent, of KOH. Potassium hydroxide, 60 Gm., distilled water, 940. 



Synonym. — Liquor potassae, B. P.; solution of potassium hydrate, solution of 

 potasli, E.; potasse caustique liquide, lessive caustique, Fr. ; aetzkalilauge, G. ; 

 liquor kali caustici, P. G. 



Derivation. — Boiling a solution of potassium carbonate with calcium hydrate 

 leaves potassium hydrate in solution, while calcium carbonate is precipitated. 

 K,C03+Ca (OH), = 2 KOH+Ca CO,. 



Properties. — A clear, colorless, odorless liquid, having, even when diluted, a 

 very acrid, caustic taste and a strongly alkaline reaction. It has a soapy feel and 

 taste. 



Dose.—n. & C, §ss-i, (15-30); Sh. & Sw., 3ss-i, (2-4); D., TTlv-xx, (.8-1.3). 



PoTASsA Cum Calce. Potassa with Lime. (Non-official.) 

 (Equal parts of potassa and lime.) 

 Synonym. — Vienna paste. 



Properties. — A grayish-white powder, deliquescent, having a strongly alkaline 

 reaction; should be soluble in diluted hydrochloric acid without leaving more 

 than a small residue. 



Action and Uses. — Potassium hydroxide, its solution, and potassa 

 cum calce are mainly of value as escharotics. Liquor potassae is unfit for 

 internal use unless greatly diluted with water. It resembles potassium 

 carbonate in its effects. Caustic potash is very destructive of tissue by 

 dissolving proteids and forming alkali-proteids. It is most diffusible and, 

 therefore, difficult to limit its action. This we may do, however, by 

 applying a plaster to a part, with a hole in it, through which the caustic 

 stick is applied. Before using the caustic, the outside of the plaster 

 should be covered with oil or grease, but not the part under the aperture 

 in it. After removing the plaster the operation of the caustic may be 

 arrested by vinegar. Cauterization by this means is very painful under 



*When solubility is mentioned hereafter, reference will be had to solubility 

 at the above temperature. 



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