See also:

• POSY (a shortened form of poesy, Fr. poesie, poetry)

POSY (a shortened See also:

• FORM (Lat. forma)

form of poesy, Fr. poesie, See also:

• POETRY

poetry)  , a See also:

• VERSE (from Lat. versus, literally a line or furrow drawn by turning the plough, from vertere, and afterwards signifying an arrangement of syllables into feet)

verse of See also:

• POETRY

poetry or a See also:

• MOTTO (an Italian word, from Late Lat. muttum, a low sound, a mutter or murmur, cf. mutere, to mutter; the Latin word also gives Fr. mot, word)

motto, either with a moral or religious sentiment or See also:

• MESSAGE (a word occurring in slightly different forms in several languages, e.g. Fr. message, Span. mensaje, Ital. messagio; adapted from the Low Lat. missaticum, from mittere)

message of love, often inscribed in a See also:

• RING (O.E. hring; a word common to Teutonic languages; and probably cognate with the Lat. circus, Gr. KtpKOS or KpLKOS, Skt'. chakra, wheel, circle, cf. also " harangue "); in art, a band of circular shape of varying sizes, made of any material and used f

ring or sent with a See also:

• PRESENT

present, such as a bouquet of See also:

• FLOWERS, ARTIFICIAL

flowers, which may be the origin of the See also:

• COMMON

common use of the. word for a nosegay or bouquet . bringing a See also:

• PLATINUM [symbol Pt, atomic weight 145.0 (0=16)]

platinum See also:

• WIRE (A.S. wir, a wire; cf. Swed. vire, to twist, M.H.G. wiere, a gold ornament, Lat. viriae, armlets, ultimately from the root wi, to twist, bind)

wire, connected to the See also:

• POSITIVE (or PORTABLE) ORGAN

positive of the See also:

• BATTERY (Fr. batterie, from battles, to beat)

battery, to the See also:

• SURFACE

surface of the See also:

• POTASSIUM [symbol K (from kalium), atomic weight 39.114 0=16)]

potassium a vivid See also:

• ACTION

action was observed: See also:

• GAS

gas was evolved at the upper surface of the fused globule of potash, whilst at the See also:

• LOWER

lower surface, adjacent to the platinum See also:

• PLATE

plate, See also:

• MINUTE
• MINUTE (Lat. minutes, small; minuere, to make less)

minute metallic globules were formed, some of which immediately inflamed, whilst others merely tarnished . In 18o8 See also:

• GAY, JOHN (1685-1732)
• GAY, MARIE FRANCOISE SOPHIE (1776-1852)
• GAY, WALTER (1856– )

Gay-Lussac and See also:

• THENARD, LOUIS JACQUES (1777-1857)

Thenard (See also:

• ANN

Ann. chim . 65, p . 325) obtained the See also:

• METAL
• METAL (through Fr. from Lat. metallum, mine, quarry, adapted from Gr. µATaXAov, in the same sense, probably connected with ,ueraAAdv, to search after, explore, µeTa, after, aAAos, other)

metal by passing melted potash down a See also:

• CLAY (from O. Eng. claeg, a word common in various forms to Teutonic languages, cf. Ger. Klei)
• CLAY, CASSIUS MARCELLUS (1810-1903)
• CLAY, CHARLES (1801–1893)
• CLAY, FREDERIC (1838–1889)
• CLAY, HENRY (1777–1852)

clay See also:

• TUBE (Lat. tuba)

tube containing See also:

• IRON [symbol Fe, atomic weight 55.85 (0=16)]

iron turnings or wire heated to whiteness, and Caradau (ibid . 66, p . 97) effected the same decomposition with See also:

• CHARCOAL

charcoal at a See also:

• WHITE
• WHITE, ANDREW DICKSON (1832– )
• WHITE, GILBERT (1720–1793)
• WHITE, HENRY KIRKE (1785-1806)
• WHITE, HUGH LAWSON (1773-1840)
• WHITE, JOSEPH BLANCO (1775-1841)
• WHITE, RICHARD GRANT (1822-1885)
• WHITE, ROBERT (1645-1704)
• WHITE, SIR GEORGE STUART (1835– )
• WHITE, SIR THOMAS (1492-1567)
• WHITE, SIR WILLIAM ARTHUR (1824--1891)
• WHITE, SIR WILLIAM HENRY (1845– )
• WHITE, THOMAS (1628-1698)
• WHITE, THOMAS (c. 1550-1624)

white See also:

• HEAT (0. E. haktu, which like " hot," Old Eng. hat, is from the Teutonic type haita, hit, to be hot; cf. Ger. hitze, heiss; Dutch, hitte, heet, &c.)

heat . This last See also:

• PROCESS

process was much improved by See also:

• BRUNNER, HENRY (184o– )

Brunner, See also:

• WOHLER, FRIEDRICH (1800-1882)

Wohler, and especially by F . M . L . Donny and J . D .

B . Mareska-(Ann. chim. phys., 1852, (3), 35, p . 147) . Brunner's process consisted in forming an intimate mixture of potassium carbonate and See also:

• CARBON (symbol C, atomic weight 12)

carbon by igniting crude See also:

• TARTAR

tartar in covered iron crucibles, cooling the See also:

• MASS (O.E. maesse; Fr. messe; Ger. Messe; Ital. messa; from eccl. Lat. missa)
• MASS, IN

mass, and then distilling it at a white heat from iron bottles, the vaporized metal being condensed beneath the surface of See also:

• PARAFFIN

paraffin or See also:

• NAPHTHA

naphtha contained in a See also:

• COPPER (symbol Cu, atomic weight 63.1, H=1, or 63.6, O = 16)

copper See also:

• VESSEL (O. Fr. vaissel, from a rare Lat. vascellum, dim. of vas, vase, urn)

vessel . It was found, however, that if the cooling be not sufficiently rapid explosions occurred owing to the See also:

• COMBINATION (Lat. combinare, to combine)

combination of the metal with carbon monoxide (produced in the oxidation of the charcoal) to See also:

• FORM (Lat. forma)

form the potassium See also:

• SALT (a common Teutonic word, cf. Dutch zout, Ger. Salz, Scand. salt; cognate with Gr. &Xs, Lat. sal)
• SALT, SIR TITUS, BART

salt of hexaoxybenzene . In Mareska and Donny's process the condensation is effected in a shallow iron See also:

• BOX
• BOX (Gr. irl or, Lat. buxus, box-wood; cf. 2r6Eir, a pyx)

box, which has a large exposed surface, capable of being cooled by damped cloths . When the See also:

• DISTILLATION (from the Lat. distillare, more correctly destillare, to drop or trickle down)

distillation is finished the iron box, after cooling, is unclamped and the product turned out beneath the surface of paraffin . It is purified by redistilling and condensing directly under paraffin . Electrolytic processes have also been devised . Linnemann (Journ . Prak . Chem., 1858, 73, p .

413) obtained the metal on a small See also:

• SCALE
• SCALE (1) A

scale by electrolysing potassium See also:

• CYANIDE

cyanide between carbon electrodes; A . Matthiessen (Journ . Chem . See also:

• SOC

Soc., 1856, p . 30) electrolysed an equimolecular mixture of potassium and See also:

• CALCIUM [symbol Ca, atomic weight 40.0 (o= x6)]

calcium chlorides (which melts at a lower temperature than potassium chloride) also between carbon electrodes; whilst Castner's process, in which See also:

• CAUSTIC (Gr. rcavvraubs, burning)

caustic potash is electrolysed, is employed commercially . The metal, however, is not in See also:

• GREAT

great demand, for it is generally found that See also:

• SODIUM [symbol Na, from Lat. natrium; atomic weight 23.00 (0=16)]

sodium (q.v.), which is cheaper, and, See also:

• WEIGHT

weight for weight, more reactive, will fulfil any purpose for which potassium may be desired . Pure potassium is a silvery white metal tinged with See also:

• BLUE (common in different forms to most European languages)

blue; but on exposure to See also:

• AIR (from an Indo-European root meaning " breathe," " blow ")
• AIR, or ASBEN

air it at once forms a film of See also:

• OXIDE

oxide, and on prolonged exposure deliquesces into a See also:

• SOLUTION (from Lat. solvere, to loosen, dissolve)

solution of See also:

• HYDRATE

hydrate and carbonate . Perfectly dry See also:

• OXYGEN (symbol 0, atomic weight 16)

oxygen, however, has no action upon it . At temperatures below o° C. it is See also:

• PRETTY

pretty hard and brittle; at the See also:

• ORDINARY (med. Lat. ordinarius, Fr. ordinaire)

ordinary temperature it is so soft that it can be kneaded between the fingers and cut with a See also:

• BLUNT, JOHN HENRY (1823–1884)
• BLUNT, JOHN JAMES (1794–1855)
• BLUNT, WILFRID SCAWEN (184o— )

blunt See also:

• KNIFE (0. E. cuff, a word appearing in different forms in many Teutonic languages, cf. Du. knijf, Ger. Kneif, a shoe-maker's knife, Swed. knif; the ultimate origin is unknown; Skeat finds the origin in the root of " nip," formerly " knip "; Fr. canif is a

knife . Its specific gravity is o•865; hence it is the lightest metal known except See also:

• LITHIUM [symbol Li, atomic weight 7•oo (0=16)]

lithium . It fuses at 62.5°C . (See also:

• BUNSEN, CHRISTIAN CHARLES JOSIAS, BARON VON (1791-186o,)
• BUNSEN, ROBERT WILHELM VON (1811-1899)

Bunsen) and boils at 667°, emitting an intensely See also:

• GREEN, A
• GREEN, ALEXANDER HENRY (1832—1896)
• GREEN, DUFF (1791—1875)
• GREEN, JOHN RICHARD (1837—1883)
• GREEN, MATTHEW (1696-1737)
• GREEN, THOMAS HILL (1836-1882)
• GREEN, VALENTINE (1739–1813)
• GREEN, WILLIAM HENRY (.1825–1900)

green vapour .

It may be obtained crystallized in quadratic octahedra of a greenish-blue See also:

• COLOUR (Lat. color, connected with celare, to hide, the root meaning, therefore, being that of a covering)

colour, by melting in a sealed tube containing an inert gas, and inverting the tube when the metal has partially solidified . When heated in air it fuses and then takes See also:

• FIRE (in O. Eng. f j'r; the word is common to West German languages, cf. Dutch vuur, Ger. Feuer; the pre-Teutonic form is seen in Sanskrit pu, pavaka, and Gr. irup; the ultimate origin is usually taken to be a root meaning to purify, cf. Lat. purus)

fire, burning into a mixture of oxides . Most remarkable, and characteristic for the See also:

• GROUP

group it represents, is its action on See also:

• WATER

water . A pellet of potassium when thrown on water at once bursts out into a See also:

• VIOLET

violet See also:

• FLAME (Lat. flamma; the root flag- appears in flagrare, to burn, blaze, and Gr. d, XEryew)

flame and the burning metal fizzes about on the surface, its extremely high temperature precluding See also:

• ABSOLUTE (Lat. absolvere, to loose, set free)

absolute contact with the liquid, except at the very end, when the last remnant, through loss of temperature, is wetted by the water and bursts with explosive violence . The reaction may be written 2K+2H20= 2KOH+H2, and the flame is due to the See also:

• COMBUSTION (from the Lat. comburere, to burn up)

combustion of the See also:

• HYDROGEN [symbol H, atomic weight x-oo8 (0=16)]

hydrogen, the violet colour being occasioned by the potassium vapour . The metal also reacts with See also:

• ALCOHOL

alcohol to form potassium ethylate, while hydrogen escapes, this See also:

• TIME (0. Eng. Lima, cf. Icel. timi, Swed. timme, hour, Dan. time; from the root also seen in " tide," properly the time of between the flow and ebb of the sea, cf. O. Eng. getidan, to happen, " even-tide," &c.; it is not directly related to Lat. tempus)
• TIME, MEASUREMENT OF
• TIME, STANDARD

time without inflammation: K+C2H5.OH = C2H5.OK+H . When the oxide-See also:

• FREE

free metal is heated gently in dry See also:

• AMMONIA (NH3)

ammonia it is gradually transformed into a blue liquid, which on cooling freezes into a yellowish-See also:

• BROWN
• BROWN, CHARLES BROCKDEN (1771-181o)
• BROWN, FORD MADOX (1821-1893)
• BROWN, FRANCIS (1849- )
• BROWN, GEORGE (1818-188o)
• BROWN, HENRY KIRKE (1814-1886)
• BROWN, JACOB (1775–1828)
• BROWN, JOHN (1715–1766)
• BROWN, JOHN (1722-1787)
• BROWN, JOHN (1735–1788)
• BROWN, JOHN (1784–1858)
• BROWN, JOHN (1800-1859)
• BROWN, JOHN (1810—1882)
• BROWN, JOHN GEORGE (1831— )
• BROWN, ROBERT (1773-1858)
• BROWN, SAMUEL MORISON (1817—1856)
• BROWN, SIR GEORGE (1790-1865)
• BROWN, SIR JOHN (1816-1896)
• BROWN, SIR WILLIAM, BART
• BROWN, THOMAS (1663-1704)
• BROWN, THOMAS (1778-1820)
• BROWN, THOMAS EDWARD (1830-1897)
• BROWN, WILLIAM LAURENCE (1755–1830)

brown or flesh-coloured solid, potassamide, KNH2 . When heated to redness the See also:

• AMIDE

amide is decomposed into ammonia and potassium nitride, NK3, which is an almost See also:

• BLACK
• BLACK, ADAM (1784-1874)
• BLACK, JEREMIAH SULLIVAN (1810–1883)
• BLACK, WILLIAM (1841-1898)

black solid . Both it and the amidedecompose water readily with formation of ammonia and caustic potash . Potassium at temperatures from Zoo°to 400°C. occludes hydrogen gas, the highest degree of saturation corresponding approximately to the See also:

• FORMULA
• FORMULA (Lat. diminutive of forma, shape, pattern, &c., especially used of rules of judicial procedure)

formula K2H . In a vacuum or in sufficiently dilute hydrogen the See also:

• COMPOUND
• COMPOUND (from Lat. componere, to combine or put together)

compound from 200° upwards loses hydrogen, until the tension of the free gas has arrived at the maximum value characteristic of that temperature (Troost and Hautefeuille) . Compounds .

Oxides and Hydroxide.—Potassium forms two well-defined oxides, 1(20 and K204, whilst several others, of less certain existence, have been described . The monoxide, 1(20, may be obtained by strongly See also:

• HEATING

heating the product or burning the metal in slightly moist air; by heating the hydroxide with,the metal: 2KHO+2K= 2K20+H2; or by passing pure and almost dry air over the molten metal (Kuhnemann, Chem . Centr., 1863, p . 491) . It forms a See also:

• GREY, CHARLES GREY, 2ND EARL (1764-1845)
• GREY, HENRY GREY, 3RD EARL (1802-1894)
• GREY, LADY JANE (1537-1554)
• GREY, SIR EDWARD
• GREY, SIR GEORGE (1812–1898)

grey brittle mass, having a conchoidal fracture; it is very deliquescent, combining very energetically with water to form caustic potash . According to See also:

• HOLT, SIR JOHN (1642–1710)

Holt and See also:

• SIMS, GEORGE ROBERT (1847– )

Sims (Journ . Chem . Soc., 1894, p . 438), the substance as obtained above always contains free potassium . Potassium hydroxide or caustic potash, KOH, formerly considered to be an oxide but shown subsequently to be a hydroxide of potassium, may be obtained by dissolving the metal or monoxide in water, but is manufactured by See also:

• DOUBLE
• DOUBLE (from the Mid. Eng. duble, the form which gives the present pronunciation, through the Old Er. duble, from Lat. duplus, twice as much)

double decomposition from potassium carbonate and slaked See also:

• LIME
• LIME (O. Eng. lim, Lat. limes, mud, from linere, to smear)

lime: K2CO3+Ca(OH)2=2KOH+CaCO2 . A solution of one See also:

• PART

part of the carbonate in 12 parts of water is heated to boiling in a See also:

• CAST (from the verb meaning " to throw "; the word is Scand. in origin, cf. Dan. kaste, and Swed. kasta; " cast " in Middle Eng. took the place of the A.S. weor pan, cf. Ger. werf en)

cast-iron vessel (industrially by means of See also:

• STEAM
• STEAM (0. Eng. steam, vapour, smoke, cf. Du. steam; the origin is unknown)

steam-pipes) and the See also:

• MILK (0. Eng. meoluc; from a common Indo-European root, cf. Lat. mulgere, Gr. ?t dXyetv)

milk of lime added in instalments until a See also:

• SAMPLE (through the O. Fr. essemple, from Lat. exemplum; a doublet of " example ")

sample of the filtered mixture no longer effervesces with an excess of See also:

• ACID (from the Lat. root ac-, sharp; acere, to be sour)

acid . The mixture is then allowed to See also:

• SETTLE
• SETTLE, ELKANAH (1648–1724)

settle in the iron vessel, See also:

• ACCESS (Lat. accessus)

access of air being prevented as much as practicable, and the clear liquor is syphoned off .

The remaining mud of calcium carbonate and hydrate is washed, by decantation, with small instalments of hot water to recover at least part of the See also:

• ALKALI

alkali diffused throughout it, but this process must not be continued too See also:

• LONG, GEORGE (1800-1879)
• LONG, JOHN DAVIS (1838– )

long or else some of the lime passes into solution . The liquors after a concentration in iron vessels are now evaporated in a See also:

• SILVER

silver dish, until the heavy vapour of the hydrate is seen to go off . The residual oily liquid is then poured out into a polished iron See also:

• TRAY

tray, or into an iron See also:

• MOULD

mould to See also:

• PRO

pro-duce the customary form of " sticks," and allowed to cool . The solid must be at once bottled, because it attracts the moisture and carbonic acid of the air with great avidity and deliquesces . According to Dittmar (Journ . Soc . Chem . Ind., May 1884), See also:

• NICKEL
• NICKEL (symbol Ni, atomic weight 58.68 (0=16))

nickel basins are far better adapted than iron basins for the preliminary concentration of potash ley . The latter begin to oxidize before the ley has come up to the traditional strength of specific gravity 1.333 when See also:

• COLD (in O. Eng. cald and ceald, a word coming ultimately from a root cognate with the Lat. gelu, gelidus, and common in the Teutonic languages, which usually have two distinct forms for the substantive and the adjective, cf. Ger. Kolte, kalt, Dutch koude

cold, while nickel is not attacked so long as the percent-See also:

• AGE (Fr. age, through late Lat. aetaticum, from aetas)

age of real KHO is See also:

• SHORT, FRANCIS JOB (1857– )

short of 6o . For the See also:

• FUSION

fusion of the dry hydrate nickel vessels cannot be used; in fact, even silver is perceptibly attacked as soon as all the excess of water is away; absolutely pure KHO can be produced only in See also:

• GOLD
• GOLD [symbol Au, atomic weight 195.7(H = 1),197.2(0 =16)]

gold vessels . See also:

• GLASS
• GLASS (O.E. glees, cf. Ger. Glas, perhaps derived from an old Teutonic root gla-, a variant of glo-, having the general sense of shining, cf. " glare," " glow ")
• GLASS, STAINED

Glass and (to a less extent) See also:

• PORCELAIN

porcelain are attacked by caustic potash ley, slowly in the cold, more readily on boiling . Solid caustic potash forms an opaque, white, See also:

• STONE
• STONE (0. Eng. shin; the word is common to Teutonic languages, cf. Ger. Stein, Du. steen, Dan. and Swed. sten; the root is also seen in Gr. aria, pebble)
• STONE, CHARLES POMEROY (1824-1887)
• STONE, EDWARD JAMES (1831-1897)
• STONE, FRANK (1800-1859)
• STONE, GEORGE (1708—1764)
• STONE, LUCY [BLACKWELL] (1818-1893)
• STONE, MARCUS (184o— )
• STONE, NICHOLAS (1586-1647)

stone-like mass of dense granular fracture; specific gravity 2.1 .

It fuses consider-ably below and is perceptibly volatile at a red heat . At a white heat the vapour breaks down into potassium, hydrogen and oxygen . It is extremely soluble in even cold water, and in any proportion of water on boiling . On crystallizing a solution, the hydrate KOH•2H20 is deposited; 2KOH•9H20 and 2KOH.5H20 have also been obtained . The solution is intensely " alkaline " to test-papers . It readily dissolves the epidermis of the skin and many other kinds of See also:

• ANIMAL
• ANIMAL (Lat. animalis, from anima, breath, soul)

animal See also:

• TISSUE (Fr. tissu, tissue, participle of tisser, Lat. texere, to weave)

tissue—hence the former application of the " sticks " in See also:

• SURGERY
• SURGERY (Fr. chirurgie, from Gr. Xetpoupyfa, i.e. hand-work)

surgery . A dilute potash readily emulsionizes fats, and on boiling saponifies them with formation of a See also:

• SOAP

soap and See also:

• GLYCERIN, GLYCERINE

glycerin . All commercial caustic potash is contaminated with excess of water (over and above that in the KHO) and with potassium carbonate and chloride; sulphate, as a See also:

• RULE

rule, is absent . A preparation sufficing for most purposes is obtained by digesting the commercial See also:

• ARTICLE (from Lat. articulus, a joint)

article in absolute alcohol, decanting and evaporating the solution to dryness and fusing in silver vessels . The peroxide, K204, discovered by Gay-Lussac and Thenard, is obtained by heating the metal in an excess of slightly moist air or oxygen . See also:

• VERNON
• VERNON, EDWARD (1684-1757)

Vernon See also:

• HARCOURT
• HARCOURT, SIMON HARCOURT, 1ST VISCOUNT (c. 1661-1727)
• HARCOURT, SIR WILLIAM GEORGE GRANVILLE VENABLES VERNON (1827-1904)
• HARCOURT, WILLIAM VERNON (1789-1871)

Harcourt (Journ . Chem .

Soc., 1862, p . 267) recommends melting the metal in a See also:

• FLASK

flask filled with See also:

• NITROGEN [symbol N., atomic weight 14.01, 0=16]

nitrogen and gradually displacing this gas by oxygen; the first formed grey film on the metal changes to a deep blue, and then the gas is rapidly absorbed, the film becoming white and afterwards yellow . It is a dark yellow See also:

• POWDER (through O. Fr. puldre, modern poudre, from Lat. pulvis, pulveris, dust)

powder,. which fuses at a high temperature, the liquid on cooling depositing shining See also:

• TABULAR

tabular crystals; at a white heat it loses oxygen and yields the monoxide . Exposed to moist air it loses oxygen, possibly giving the dioxide, K202 ; water reacts with it, evolving much heat and giving caustic potash, hydrogen peroxide and oxygen; whilst carbon monoxide gives potassium carbonate and oxygen at temperatures below too° . A violent reaction ensues with See also:

• PHOSPHORUS (Gr. 4ws, light, sPEpety, to bear)

phosphorus and See also:

• SULPHUR

sulphur, and many metals are oxidized by it, some with incandescence . Halogen Compounds.—Potassium fluoride, KF, is a very deliquescent salt, crystallizing in cubes and having a See also:

• SHARP, GRANVILLE (1735-1813)
• SHARP, JAMES (1618-1679)
• SHARP, JOHN (1645-1714)
• SHARP, RICHARD (1759-1835)
• SHARP, WILLIAM (1749-1824)
• SHARP, WILLIAM (1856-1905)

sharp saline See also:

• TASTE (from Lat. taxare, to touch sharply; tangere, to touch)

taste, which is formed by neutralizing potassium carbonate or hydroxide with hydrofluoric acid and concentrating in platinum vessels . It forms the acid fluoride KHF2 when dissolved in aqueous hydrofluoric acid, a salt which at a red heat gives the normal fluoride and hydrofluoric acid . Other salts of See also:

• COMPOSITION
• COMPOSITION (Lat. compositio, from componere, to put together)

composition KF•2HF and KF•3HF, have been described by See also:

• MOISSAN, HENRI (1852-1907)

Moissan (See also:

• COMET (Gr. Koµieiis, long-haired)

Comet. rend., i888, io6, p . 547) . Potassium chloride, KC1, also known as muriate of potash, closely resembles ordinary salt . It is produced in immense quantities at See also:

• STASSFURT

Stassfurt from the so-called " Abraumsalze." For the purpose of the manufacturer of this salt these are assorted into a raw material containing approximately, in See also:

• LOO (formerly called " Lanterloo," Fr. lanturlu, the refrain of a popular 17th-century song)

loo parts, 55–65 of carnallite (representing i6 parts of potassium chloride), 20–25 of common salt, 15—20 of kieserite; 2–4 of tachhydrite (CaC12.2MgC12.12H20), and See also:

• MINOR
• MINOR (Lat. for smaller, lesser)
• MINOR, ROBERT CRANNELL (1839-1904)

minor components . This mixture is now wrought mainly in two ways .

(I) The salt is dissolved in water with the help of steam, and the solution is cooled down to from 6o° to 70°, when a quantity of impure common salt crystallizes out, which is removed . The decanted ley deposits on See also:

• STANDING

standing a 70% potassium chloride, which is purified by washing with cold water . Common salt principally goes into solution, and the percentage may thus be brought up to from 8o to 95 . The See also:

• MOTHER

mother-liquor from the 70% chloride is evaporated, the common salt which separates out in the heat removed as it appears, and the sufficiently concentrated liquor allowed to crystallize, when almost pure carnallite separates out, which is easily decomposed into its components (see infra) . (2) Ziervogel and Tuchen's method.—The crude salt is ground up and then heated in a concentrated solution of See also:

• MAGNESIUM [symbol Mg, atomic weight 24.32 (0 = 16)]

magnesium chloride with agitation . The carnallite principally dissolves and crystallizes out relatively pure on cooling . The mother-liquor is used for a subsequent extraction of fresh raw salt . The carnallite produced is dissolved in hot water and the solution allowed to cool, when it deposits a coarse granular potassium chloride containing up to 99 i° of the pure substance . The undissolved See also:

• RESIDUE (through the French, from the Lat. residuum, a remainder, from residere, to remain)

residue produced in either process consists chiefly of kieserite and common salt . It is worked up either for See also:

• EPSOM

Epsom salt and common salt, or for sodium sulphate and magnesium chloride . The potassiferous by-products are utilized for the manufacture of See also:

• MANURES

manures . Chemically pure chloride of potassium is most conveniently prepared from the pure perchlorate by heating it in a platinum See also:

• BASIN, or BASON (the older form bacin is found in many of the Romanic languages, from the Late Lat. baccinus or bacchinus, probably derived from bacca, a bowl)
• BASIN, THOMAS (1412—1491)

basin at the lowest temperature and then fusing the residue in a well-covered platinum crucible .

The fused product solidifies on cooling into a colourless glass . When hydrochloric acid gas is passed into the solution the salt is completely precipitated as a See also:

• FINE

fine powder . If the See also:

• ORIGINAL

original solution contained the chlorides of magnesium or calcium or sulphate of potassium all impurities remain in the mother-liquor (the sulphur as KHSO4), and can be removed by washing the precipitate with strong hydrochloric acid . The salt crystallizes in cubes of specific gravity 1.995; it melts at about 800° and volatilizes at a See also:

• BRIGHT, JOHN (1811-188g)
• BRIGHT, SIR CHARLES TILSTON

bright red heat . When melted in a current of hydrogen or electrolysed in the same See also:

• CONDITION (Lat. condicio, from condicere, to agree upon, arrange; not connected with conditio, from condere, conditum, to put together)

condition, a dark blue mass is obtained of uncertain composition . It is extensively employed for the preparation of other potassium salts, but the largest quantity (especially of the impure product) is used in the See also:

• PRODUCTION (Lat. productionem, from producere, to pro-duce)

production of artificial manures . Potassium bromide, KBr, may be obtained by dissolving See also:

• BROMINE (symbol Br, atomic weight 79-96)

bromine in potash, whereupon bromide and bromate are first formed, evaporating and igniting the product in See also:

• ORDER
• ORDER (through Fr. ordre, for earlier ordene, from Lat. ordo, ordinis, rank, service, arrangement; the ultimate source is generally taken to be the root seen in Lat. oriri, rise, arise, begin; cf. " origin ")
• ORDER, HOLY

order to decompose the bromate: 6KHO + 3Br2=5KBr + KBrO3 + 3H2O; 2KBrO3 = 2KBr + 302 (cf . See also:

• CHLORATES

CHLORATES) ; but it is manufactured by acting with bromine water on iron filings and decomposing the iron bromide thus formed with potassium carbonate . In See also:

• APPEARANCE (from Lat. apparere, to appear)

appearance it closely resembles the chloride, forming colourless cubes which readily dissolve in water and melt at 722° . It combines with bromine to form an unstable tribromide, KBr3 (see F . P . Worley, Journ .

Chem . Soc., 1905, 87, p . 1107) . Potassium iodide, KI, is obtained by dissolving See also:

• IODINE (symbol I, atomic weight '26.92)

iodine in potash, the deoxidation of the iodate being facilitated by the addition of charcoal before ignition, proceeding as with the bromide . The commercial salt usually has an alkaline reaction; it may be purified by dissolving in the minimum amount of water, and neutralizing with dilute sulphuric acid; alcohol is now added to precipitate the potassium sulphate, the solution filtered and crystallized . It forms colourless cubes which are readily soluble in water, melt at 685°, and yield a vapour of normal See also:

• DENSITY (Lat. densus, thick)

density . It is sparingly soluble in absolute alcohol . Both the iodide and bromide are used in See also:

• PHOTOGRAPHY (Gr. bias, light, and ypa w, to write)
• PHOTOGRAPHY, CELESTIAL

photography . Iodine dissolves in an aqueous solution of the salt to form a dark brown liquid, which on evaporation over sulphuric acid gives black acicular crystals of the tri-iodide, KI3 . This salt is very deliquescent; it melts at 45° and at zoo° decomposes into iodine and potassium iodide . For the oxyhalogen salts see CHLORATE, See also:

• CHLORINE (symbol Cl, atomic weight 35`46 (0=16)

CHLORINE, BROMINE and IODINE . Potassium carbonate, K2CO3, popularly known as " See also:

• POTASHES

potashes," was originally obtained in countries where See also:

• WOOD, ANTHONY A2 (1632-1695)
• WOOD, JOHN GEORGE (1827—1889)
• WOOD, MRS HENRY [ELLEN] (1814—1887)
• WOOD, SEARLES VALENTINE (1798—188o)

wood was cheap by lixiviating wood ashes in wooden tubs, evaporating the solution to dryness in iron pots and calcining the residue; in more See also:

• RECENT

recent practice the calcination is carried out in reverberatory furnaces .

This product, known as " crude potashes," contains, in additionto carbonate, varying amounts of sulphate and chloride and also insoluble See also:

• MATTER

matter . Crude potash is used for the manufacture of glass, and, after being causticized, for the making of soft soap . For many other purposes it must be refined, which is done by treating the crude product with the minimum of cold water required to dissolve the carbonate, removing the undissolved part (which consists chiefly of sulphate), and evaporating the clear liquor to dryness in an iron See also:

• PAN (" pasturer ")
• PAN (common in various forms to many Teutonic languages, cf. Ger. Pfanne; it is generally taken to be an early adaptation in a shortened form of Lat. patina, shallow bowl or dish, from patere, to lie open)

pan . The purified carbonate (which still contains most of the chloride of the raw material and other impurities) is known as " See also:

• PEARL
• PEARL, THE

pearl ashes." Large quantities of carbon-See also:

• ATE

ate used to be manufactured from the aqueous residue See also:

• LEFT

left in the distillation of See also:

• BEET

beet-See also:

• ROOT (late O.E. rot, adopted from Scand., cf. Norw. and Swed. rot, Dan. rod; the true O.E. word was wyrt, plant, represented in Ger. Wurz or Wurzel; the ultimate root is the same in both words, and is seen in Lat. radix)
• ROOT, ELIHU (1845– )

root spirit, i.e. indirectly from beet-root See also:

• MOLASSES

molasses . The liquors are evaporated to dryness and the residue is ignited to obtain a very impure carbonate, which is purified by methods founded on the different solubilities of the several components . Most of the carbonate which now occurs in See also:

• COMMERCE
• COMMERCE (Lat. commercium, from, cum, together, and rnerx, merchandise)

commerce is made from the chloride of the Stassfurt beds by an See also:

• ADAPTATION (from Lat. adaptare. to fit to)

adaptation of the " Leblanc process " for the See also:

• CONVERSION (Lat. conversio, from convertere, to turn or ,change)

conversion of common salt into soda ash (see ALKALI MANUFACTURE) . Chemically pure carbonate of potash is best prepared by igniting pure bicarbonate (see below) in iron or (better) in silver or platinum vessels, or else by calcining pure cream of tartar . The latter operation furnishes an intimate mixture of the carbonate with charcoal, from which the carbonate is extracted by lixiviation with water and filtration . The filtrate is evaporated to dryness (in iron or platinum vessels) and the residue fully dehydrated by See also:

• GENTLE (through the Fr. gentil, from Lat. gentilis, belonging to the same gens, or family)

gentle ignition . The salt is thus obtained as a white porous mass, fusible at a red heat (838° C., Carnelley) into a colourless liquid, which solidifies into a white opaque mass . The dry salt is very hygroscopic; it deliquesces into an oily solution (" oleum tartari ") in ordinary air . The most saturated solution contains 205 parts of the salt to too of water and boils at 135° .

On crystallizing a solution See also:

• MONOCLINIC

monoclinic crystals of 2K2CO3.3H20 are deposited, which at too° lose water and give a white powder of K2CO3•H20; this is completely dehydrated at 130° . The carbonate, being insoluble in strong alcohol (and many other liquid organic compounds), is much used for dehydration of the corresponding aqueous preparations . The pure carbonate is constantly used in the laboratory as a basic substance generally, for the disintegration of silicates, and as a precipitant . The See also:

• INDUSTRIAL

industrial preparation serves for the making of See also:

• FLINT
• FLINT, AUSTIN (1812-1886)
• FLINT, or FLTNTSHTRE (sir Gallestr)
• FLINT, ROBERT (1838- )
• FLINT, TIMOTHY (1780-1840)

flint glass, of potash soap (soft soap) and of caustic potash . Potassium bicarbonate, KHCO3, is obtained when carbonic acid is passed through a cold solution of the ordinary carbonate as long as it is absorbed . Any silicate present is also converted into bicarbonate with elimination of See also:

• SILICA

silica, which must be filtered off . The filtrate is evaporated at a temperature not exceeding 6o° or at most 7o° C.; after sufficient concentration it deposits on cooling anhydrous crystals of the salt, while the potassium chloride, which may be present as an impurity, remains mostly in the mother-liquor; the See also:

• REST (O. Eng. rest, reste, bed, cognate with other Teutonic forms, e.g. Ger. Rast, Riiste, rest, and probably Gothic Rasta, league, i.e. resting or stopping place)

rest is easily removed by repeated recrystallization . If an absolutely pure preparation is wanted it is best to follow Wohler and start with the " black See also:

• FLUX (Lat. fluxus, a flowing; this being also the meaning of the English term in medicine, &c.)

flux " produced by the ignition of pure bitartrate . The flux is moistened with water and exposed to a current of carbonic acid, which, on See also:

• ACCOUNT
• ACCOUNT (through O. Fr. acont, Late Lat. comptum, cornputare, to calculate)

account of the condensing action of the charcoal, is absorbed with great avidity . The bicarbonate forms large monoclinic prisms, permanent in the air . When the dry salt is heated to 19o° it decomposes into normal carbonate, carbon dioxide and water . Potassium sulphide, K2S, was obtained by See also:

• BERZELIUS, JONS JAKOB (1779-1848)

Berzelius in See also:

• PALE (through Fr. pal, from Lat. palms, a stake, for paglus, from the stem pag- of pangere, to fix; " pole " is from the same original source)

pale red crystals by passing hydrogen over potassium sulphate, and by See also:

• BERTHIER, LOUIS ALEXANDRE

Berthier as a flesh-coloured mass by heating the sulphate with carbon .

It appears, however, that these products contain higher sulphides . On saturating a solution of caustic potash with sulphuretted hydrogen and adding a second See also:

• EQUIVALENT

equivalent of alkali, a solution is obtained which on evaporation in a vacuum deposits crystals of K2S.5H2O . The solution is strongly caustic . It turns yellow on exposure to air, absorbing oxygen and carbon dioxide and forming thiosulphate and potassium carbonate and liberating sulphuretted hydrogen, which decomposes into water and sulphur, the latter combining with the monosulphide to form higher salts . The solution also decomposes on boiling . The hydrosulphide, KHS, was obtained by Gay-Lussac on heating the metal in sulphuretted hydrogen, and by Berzelius on acting with sulphuretted hydrogen on potassium carbonate at a dull red heat . It forms a yellowish-white deliquescent mass, which melts on heating, and at a sufficiently high temperature it yields a dark red liquid . It is readily soluble in water, and on evaporation in a vacuum over caustic lime it deposits colourless, See also:

• RHOMBOHEDRAL

rhombohedral crystals of 2KHS.H20 . The solution is more easily prepared by saturating potash solution with sulphuretted hydrogen . The solution has a See also:

• BITTER, KARL THEODORE FRANCIS (1867– )

bitter taste, and on exposure to the air turns yellow, but on long exposure it recovers its original colourless appearance owing to the formation of thiosulphate . See also:

• LIVER (O. Eng. lifer; cf. cognate forms, Dutch lever, Ger. Leber, Swed. lefver, &c.; the O. H. Ger. forms are libara, lipora, &c.; the Teut. word has been connected with Gr. i'prap and Lat. jecur)

Liver of sulphur or he See also:

• PAR (Lat. par, equal)

par sulphuris, a See also:

• MEDICINE

medicine known to the alchemists, is a mixture of various poly-sulphides with the sulphate and thiosulphate, in variable proportions, obtained by gently heating the carbonate with sulphur in covered vessels . It forms a liver-coloured mass .

In the See also:

• PHARMACOPOEIA (lit. the art of the OapµaK07robbs, or drug-compounder)

pharmacopoeia it is designated potassa sulphurata . Potassium sulphite, K2SO3, is prepared by saturating a potash solution with sulphur dioxide, adding a second equivalent of potash, and crystallizing in a vacuum, when the salt separates as small deliquescent, hexagonal crystals . The salt K2SO3.H20 may be obtained by crystallizing the metabisulphite, K2S205 (from sulphur dioxide and a hot saturated solution of the carbonate, or from sulphur dioxide and a mixture of milk of lime and potassium sulphate) with an equivalent amount of potash . The salt K2SO3•2H20 is obtained as oblique rhombic octahedra by crystallizing the solution over sulphuric acid . On the isomeric potassium sodium sulphites see SULPHUR . Potassium sulphate, K2SO4, a salt known See also:

• EARLY
• EARLY, JUBAL ANDERSON (1816-1894)

early in the 14th See also:

• CENTURY (from Lat. centuria, a division of a hundred men)

century, and studied by See also:

• GLAUBER, JOHANN RUDOLF (1604-1668)

Glauber, See also:

• BOYLE
• BOYLE, JOHN J
• BOYLE, ROBERT (1627-1691)

Boyle and Tachenius, was styled in the 17th century arcanum or sal duplicatum, being regarded as a combination of an acid salt with an alkaline salt . It was obtained as a by-product in many chemical reactions, and subsequently used to be extracted from kainite, one of the Stassfurt minerals, but the process is now given up because the salt can be produced cheaply enough from the chloride by decomposing it with sulphuric acid and calcining the residue . To purify the crude product it is dissolved in hot water and the solution filtered and allowed to cool, when the bulk of the dissolved salt crystallizes out with characteristic promptitude . The very beautiful (anhydrous) crystals have the See also:

• HABIT (through the French from Lat. habitus, from habere, to have, hold, or, in a reflective sense, to be in a certain condition; in many of the English senses the French use habitude, not habit)

habit of a double six-sided See also:

• PYRAMID

pyramid, but really belong to the rhombic See also:

• SYSTEM

system . They are transparent, very hard and absolutely permanent in the air . They have a bitter, salty taste . The salt is soluble in water, but insoluble in caustic potash of sp. gr .

1.35, and in absolute alcohol . It fuses at 1078° . The crude salt is used occasionally in the manufacture of glass . The acid sulphate or bisulphate, KHSO4, is readily produced by fusing thirteen parts of the powdered normal salt with eight parts of sulphuric acid . It forms rhombic pyramids, which melt at 197° . It dissolves in three parts of water of o° C . The solution behaves pretty much as if its two congeners, K2SO4 and H2SO4, were present See also:

• SIDE
• SIDE (mod. Eski Adalia)

side by side of each other uncombined . An excess of alcohol, in fact, precipitates normal sulphate (with little bisulphate) and free acid remains in solution . Similar is the behaviour of the fused dry salt at a dull red heat; it acts on silicates, titanates, &c., as if it were sulphuric acid raised beyond its natural boiling point . Hence its frequent application in See also:

• ANALYSIS (Gr. avci and Meta, to break up into parts)

analysis as a disintegrating See also:

• AGENT (from Lat. agere, to act)

agent . For the salts of other sulphur acids, see SULPHUR . Potassamide, NH2K, discovered by Gay-Lussac and Thenard in 1871, is obtained as an See also:

• OLIVE (Olea europaea)

olive green or brown mass by gently heating the metal in ammonia gas, or as a white, waxy, crystalline mass when the metal is heated in a silver See also:

• BOAT (0. Eng. bdt; the true etymological connexion with Dutch and Ger. boot, Fr. bateau, Ital. battello presents great difficulties; Celtic forms are from O. Eng.)

boat .

It decomposes in moist air, or with water, giving caustic potash and ammonia, in the latter See also:

• CASE
• CASE, JOHN (d. 1600)

case with considerable See also:

• EVOLUTION

evolution of heat . On strong heating Tithesley (Journ . Chem . Soc., 1894, p . 511) found that it decomposed into its elements . For the nitrite, see NITROGEN, for the nitrate see See also:

• SALTPETRE (from the Lat. sal, salt, Petra, a rock)

SALTPETRE and for the cyanide see PRUSSIC ACID; for other salts see the articles wherein the corresponding acid receives treatment . Analysis, &c.—All volatile potassium compounds impart a violet coloration to the Bunsen flame, which is masked, however, if sodium be present . The emission spectrum shows two lines, Ka, a double See also:

• LINE

line towards the infra-red, and K/3 in the violet . The See also:

• CHIEF (from Fr. chef, head, Lat. caput)

chief insoluble salts are the perchlorate, acid-tartrate and platinochloride . The atomic weight was determined by See also:

• STAS, JEAN SERVAIS (1813–1891)

Stas and more recently by T . W . See also:

• RICHARDS, ALFRED BATE (182o-1876)
• RICHARDS, HENRY BRINLEY (1819-1865)
• RICHARDS, WILLIAM TROST (1833-1905)

Richards and A .

Stahler, who obtained the value 39.114 from analyses of the chloride, and by Richards and E . Meuller, who obtained the values 39.1135 and 39.1143 from analyses of the bromide (see Abs . J . C . S., 1907, ii . 615) . Medicine . See also:

• PHARMACOLOGY

Pharmacology.—Numerous salts and preparations of potassium are used in medicine; viz . Potassii Carbonis (salt of tartar), dose 5 to 20 grs., from which are made (a) Potassii Bicarbonas, dose 5 to 30 grs.; (b) Potassa Caustica, a powerful caustic not used internally . From caustic potash are made (I) Potassii Permanganas, dose I to 3 grs., used in preparing Liquor Potassii Permanganatis, a 1% solution, dose 2 to 4 drs . (2) Potassii lodidum, dose 5 to 20 grs.; from this are made the Linamentum Potassii lodidi cum sapone, strength 1 in to, and the Unguentum Potassii lodidi, strength I in to . (3) Potassii Bromidum, dose 5 to 30 grs .

(4) Liquor Potassae, strength 27 grs. of caustic potash to the oz . Potassii Citras, dose to to 40 grs . Potassii Acetas, dose Io to 6o grs . Potassii Chloras, dose 5 to 15 grs., from which is made a See also:

• LOZENGE (from the Fr. losenge, or losange; the word also appears in Span. losanje, and Ital. losanga; perhaps derived from a word meaning a stone slab laid on a grave, which appears in forms such as Provencal lousa, Span. losa, the ultimate origin of whic

lozenge, Trochiscus Potassii Chloratis, each containing 3 grs . Potassii Tartras Acidus (cream of tartar), dose 20 to 6o grs., which has a subpreparation Potassii Tartras, dose 30 to 6o grs . Potassii Nitras (saltpetre), dose 5 to 20 grs . Potassii Sulphas, dose lo to 40 grs . Potassii Sickrooms, dose to i gr . See also:

• TOXICOLOGY

Toxicology.—Poisoning by caustic potash may take See also:

• PLACE (through Fr. from Lat. platea, street; Gr. IrAar6s, wide)

place or poisoning by pearl ash containing caustic potash . A caustic taste in the mouth is quickly followed by burning abdominal See also:

• PAIN (from Lat. poena, Gr. robin, penalty, that which must be paid: O. Fr. peine)
• PAIN, BARRY (1867– )

pain, vomiting and See also:

• DIARRHOEA (from Gr. &Q, through, pfw, flow)

diarrhoea, with a feeble See also:

• PULSE

pulse and a cold clammy skin; the See also:

• POST

post-mortem appearances are those of acute gastrointestinal irritation . The treatment is washing out the See also:

• STOMACH (Gr. vrbsaxos from arbga, a mouth)

stomach or giving See also:

• EMETICS (from Gr. inerucos, causing vomit)

emetics followed by See also:

• VINEGAR

vinegar or See also:

• LEMON
• LEMON, MARK (1809-1870)

lemon juice and later oil and white of See also:

• EGG (O.E. aeg, cf. Ger. Ei, Swed. aegg, and prob. Gr. u,ov, Lat. ovum)
• EGG, AUGUSTUS LEOPOLD (1816-1863)

egg . See also:

• THERAPEUTICS (Gr. BepaaeuTLKIi, Sc. TEXVrt, from Beparebsty, to serve)

Therapeutics.—Externally: Caustic potash is a most powerful irritant and caustic; it is used with lime in making See also:

• VIENNA (Ger. Wien; Lat. Vindobona)
• VIENNA, CONGRESS OF (1814-1815)

Vienna See also:

• PASTE (O. Fr. paste, modern pate, Late Lat. pasta, whence also in Span., Port. and Ital., from Gr. 1r&vrrl or 1raara, barley porridge, or salted pottage, ir&ao'ety, to sprinkle with salt)

paste,which is occasionally used to destroy morbid growths .

Liquor potassae is also used in certain skin diseases . The permanganate of potash is an irritant if used pure . Its See also:

• PRINCIPAL

principal action is as an antiseptic and disinfectant . If wet it oxidizes the products of decomposition . It is used in the dressing of_foul ulcers . The 1% solution is an antidote for snake-bite . Internally: Dilute solutions of potash, like other alkalis, are used to neutralize the poisonous effects of strong acids . In the stomach potassium salts neutralize the gastric acid, and hence small doses are useful in hyperchloridia . Potassium salts are strongly diuretic, acting directly on the renal epithelium . They are quickly excreted in the urine, rendering it alkaline and thus more able to hold uric acid in solution . They also hinder the formation of uric acid calculi . The acetate and the citrate are valuable mild diuretics in Bright's disease and in feverish conditions, and by increasing the amount of urine diminish the pathological fluids in pleuritic effusion, See also:

• ASCITES (Gr. aaKLTl7s, dropsical, from a.QKOS, bag; sc. v6aos, disease)

ascites, &c .

In tubal nephritis they aid the See also:

• EXCRETION (Lat. ex, out of, cernere, cretum, to separate)

excretion of fatty casts . The tartrate and acid tartrate are also diuretic in their action and, as well as the sulphate, are valuable hydragogue saline purgatives . Potassium nitrate is chiefly used to make See also:

• NITRE

nitre See also:

• PAPER
• PAPER (Fr. papier, from Lat. papyrus)

paper, which on burning emits fumes useful in the treatment of the asthmatic See also:

• PAROXYSM (Med. Lat. paroxysntus, from the Gr. wapotbvety, to make sharp, odes)

paroxysm . Lozenges of potassium chlorate are used in stomatitis, tonsilitis and See also:

• PHARYNGITIS

pharyngitis, it can also be used in a gargle, Io grs. to I fl. oz. of water . Its therapeutic action is said to be due to nascent oxygen given off, so it is See also:

• LOCAL

local in its action . In large doses it is a dangerous See also:

• POISON

poison, converting the oxyhaemoglobin of the See also:

• BLOOD

blood into methaemoglobin . Internally the permanganate is a valuable antidote in See also:

• OPIUM (Gr. amov, dim. from Orbs, juice)

opium poisoning . The action of potassium bromide and potassium iodide has been treated under bromine and iodine (q.v.) . All potassium salts if taken in large doses are cardiac depressants, they also depress the See also:

• NERVOUS

nervous system, especially the See also:

• BRAIN (A.S. braegen)

brain and See also:

• SPINAL

spinal See also:

• CORD (derived through the Fr. corde, from the Lat. chorda, Gr. xop(5rt, the string of a musical instrument)

cord . Like all alkalis if given in quantities they increase See also:

• METABOLISM (from Gr. ,uera(3oXh, change)

metabolism .