106 INORGANIC AGENTS 



They are sometimes prescribed in, fever on account of slight diaphoretic 

 and powerful diuretic properties. 



Potassium acetate and citrate stimulate bronchial secretion and make 

 it thinner, and are recommended accordingly in bronchitis. They are 

 less efficient than potassium iodide for these purposes in this affection. 



Diuretic, diaphoretic and expectorant mixture for fever with bronchitis in 

 horses. 



^ Tincturae aconiti 3iii 



Potassii citratis giv 



Spiritus setheris nitrosi Sviii 



Aquae ad Oi 



M. 



Sig. 4 tablespoonfuls in drinking water 3 times daily. 



Potassii Nitras. Potassium Nitrate. KNO3 (U. S. & B. P.). 



Synonym. — Nitre, saltpetre, E.; nitre prismatique, azotate (nitrate) de 

 potasse, Fr.; saltpetersaures kali, kalisalpeter, G. 



Derivation.— Saltpetre is formed in the soil in certain regions and climates 

 and is made artificially, by the putrefaction of animal or vegetable material, in 

 the presence of heat, moisture, oxygen, and alkaline or earthy bases capable of 

 fixing the nitric acid set free in this process, known as nitrification. Tlie natural 

 conditions for nitrification are present in some parts of India, and saltpetre is 

 largely imported from Calcutta. Artificially, nitre beds are made of animal and 

 vegetable matter, wood ashes, and calcareous earth or old plaster from houses. 

 Sodium nitrate is imported extensively from Chili, where it occurs as a mineral 

 product, and is used widely in this country in artificial fertilizers. Chili saltpetre 

 may be converted into nitre by treatment with potash. 



Properties. — ^Colorless, transparent, six-sided, rhombic prisms, or a white, 

 crystalline powder; odorless, and having a saline taste and producing a cooling 

 sensation in the mouth. Slightly hygroscopic in moist air. Soluble in 2.8 parts 

 of water; in 620 parts of alcohol. 



Dose.— H. & C, gss-i, (15-80) ; Sh. & Sw., 3ss-i, (2-4,) ; D., gr.v-xx, (.3-1.3). 



Action External. — Refrigerant. 



Action Internal. — Stomach and Intestines. — Nitre causes, in lethal 

 doses, violent gastro-enteritis, often nephritis, muscular weakness, coma, 

 collapse and depression of the circulation. The pulse becomes both slow 

 and weak. There is muscular weakness and paralysis. Potassium nitrate 

 is one of the most irritating salts of this group, but its toxic effect de- 

 pends upon the influence of the nitrate ion, and — ^when concentrated — 

 upon its "salt action" (see p. 115) in withdrawing water from the tissues. 



Blood. — Toxic doses of nitre have a slight destructive action (hemo- 

 lysis) on the red blood cells. 



Heart. — Nitre is said to be more depressing to the heart than the 

 other potassium compounds. There is no basis for this belief. 



Lungs. — The respiration is slowed by considerable doses of potas- 

 sium nitrate, and it exerts an antispasmodic action by depression of the 

 unjjriped fibres of the bronchi. It has an expectorant action similar to 

 that of the acetate and citrate of potash. 



Kidneys. — Diuresis is the predominant medicinal action of nitre. It 

 may induce diuresis through its "salt action" (see p. 115) but in that case 

 should escape unchanged in the urine. Apparently little or none is thus 

 eliminated, except after large doses. In moderate doses the salt is 

 changed in the body. It is conjectured that it is first converted into 



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