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POTASH, NITRATE OP 



POTASH, BICARBONATE OP, is prepared by passing carbonic acid through 

 a solution of the carbonate of potash. See BICARBONATES. 



POTASH, BICHROMATE OF. See CHROMATES OF POTASH. 



POTASH, BINOXAI.ATE OP. Salt of wood sorrel; Salt of sorrel ; Sal 

 acetosella. (Set d'oseille, Fr.) 



The Oxalis acetosella is an odourless plant, but in taste it is agreeably acidulous. 



In some parts of Germany the binoxalate of potash is obtained in large quantities 



from this plant by evaporating the expressed juice. Five hundred parts of the plant 



yield four parts of the crystallised salt ; its composition is, oxalic acid 2 parts, 



potasli 1 part, water 2 parts. 



It is sold under the name of salt of lemons, sometimes in a pure state, but more fre- 

 quently mixed with cream of tartar, and is used for the removal of iron stains from 

 linen. 



POTASH, BITARTRATE OP. Cream of tartar. This salt is a constituent of 

 many vegetable juices, especially of the juice of the grape. All the salt of commerce 

 is obtained during the vinous fermentation ; it deposits during the process of the for- 

 mation of alcohol, and accordingly as it is obtained from white or red wine it is known 

 by the name of white or red argol. The acid tartar is thus prepared in the wine- 

 making districts of France. 



Argol, which occurs in crystalline cakes, and is composed of the bitartrate of potash, 

 tartrate of lime, and colouring-matter, is boiled in water ; and the solution allowed to 

 cool, by which a deposit of crystals is obtained. These are washed with cold water, 

 and then dissolved in boiling water, in which are diffused clay and charcoal, which as 

 they fall down receive the colouring-matter. The clear liquor is allowed to cool slowly, 

 and crystals form. 



This salt consists of potash 25*00, tartaric acid 70-21, water 4-79. 



If cream of tartar is heated it is decomposed, swells up, evolves gaseous products, 

 and is converted into Black Flux. See ASSAYING. 



POTASH, CARBONATE OF. Salt of tartar ; Potashes; Pearlashes. If land 

 plants are burnt their ashes will be found to contain a considerable quantity of the 

 carbonate of potash. 



Carbonate of potash is composed of 48 parts of base and 22 of acid ; or, in 100 

 parts, of 68-09 of potash and 31-91 of carbonic acid : that is, KO.CO* (X 2 CO S ). 



Carbonate of potash, as it exists associated with carbon in calcined tartar, passes 

 very readily into the bicarbonate, on being moistened with water, and having .1 current 

 of carbonic acid gas passed through it. The absorption takes place so rapidly, that 

 the mass becomes hot, and therefore ought to be surrounded with cold water. See 

 POTASH. 



POTASH, CAUSTIC. See POTASH. 



POTASH, CHLORATE OP. See CHLOBATE OF POTASH. 



POTASH, CITRATE OP. This salt is formed by neutralising citric acid with 

 carbonate of potash. Under the names of lemon and kali, effervescing lemonade, and 

 the like, mixtures of dry citric ncid in powder and dry carbonate of potash, with very 

 dry sugar, are sold. These form very agreeable and healthful beverages. 



POTASH, HYDRATE OF, or CAUSTIC POTASH. (Potasse, Fr. ; Kali, 

 Ger.) It may be obtained thus: Mix a solution of 1 part of the dry carbonate of 

 potash with 1 part of freshly-prepared dry hydrate of lime, and allow it to stand in a 

 closed vessel for 24 hours at a temperature of 68 to 78 Fahr., frequently shaking it. 

 The potash salt should be dissolved in 12 to 15 parts of water ; the carbonate of lime 

 separates in a granulated state, and the clear caustic lye may be decanted. A weaker 

 lye may be obtained from the residue by fresli treatment with water. See POTASH. 



POTASH, NITRATE OF. KO.NO* (XWO S .) Syns. Xitre, Saltpetre, Prismatic 

 nitre. (Nitrate de potasse, Fr. ; Salpetersaures Kali, Ger.) For the mode of purifica- 

 tion, see GUNPOWDKR. This well-known and useful salt is found native in various 

 parts of the world, more especially in tropical climates. The formation of nitre in 

 the earth appears to be much facilitated by warmth. 





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