See also:

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

SALTPETRE (from the See also:

• LAT

Lat. sal, 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, See also:

• PETRA (r)

Petra, a See also:

• ROCK
• ROCK (O.Fr. rake, Sp. rota, Ital. rocca; possibly from a Lat. form rupica, from rupes, rock)
• ROCK, DANIEL (1799–187t)

rock)  , the commercial name given to three naturally occurring nitrates, distinguished as (1) See also:

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

ordinary See also:

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

saltpetre, See also:

• NITRE

nitre, or See also:

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

potassium nitrate, (2) See also:

• CHILE, or CHILI (derived, it is said, from the Quichua chin , cold, or tchili, snow)

Chile saltpetre, cubic nitre, or See also:

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

sodium nitrate, (3) See also:

• WALL (O. Eng. weal, weall, Mid. Eng. wal, wane, adapted from Lat. vallum, rampart; the original O. Eng. word for a wall was wag or tenth)
• WALL, RICHARD (1694-1778)

wall-saltpetre or See also:

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

calcium nitrate . These nitrates generally occur as efflorescences caused by the oxidation of nitrogenous See also:

• MATTER

matter in the presence of the alkalies and alkaline earths . r . Ordinary Saltpetre or Potassium Nitrate, KNO3, occurs, mingled with other nitrates, on the See also:

• SURFACE

surface and in the superficial layers of the See also:

• SOIL

soil in many countries, especially in certain parts of See also:

• INDIA
• INDIA, FRENCH

India, See also:

• PERSIA

Persia, See also:

• ARABIA

Arabia and See also:

• SPAIN
• SPAIN (Espana)

Spain . The deposits in the See also:

• GREAT

great See also:

• LIMESTONE

limestone caves of See also:

• KENTUCKY

Kentucky, See also:

• VIRGINIA
• VIRGINIA, or VERGINIA
• VIRGINIA, UNIVERSITY OF

Virginia and See also:

• INDIANA

Indiana have been probably derived from the overlying soil and accumulated by percolating See also:

• WATER

water; they are of no commercial value . The actual formation of this 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 is not quite clear; but it is certainly conditioned by the simultaneous contact of decaying nitrogenous matter, alkalies, See also:

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

air and moisture . The demand for saltpetre as an ingredient of See also:

• GUNPOWDER

gunpowder led to the formation of saltpetre plantations or nitriaries, which at one 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 were See also:

• COMMON

common in See also:

• FRANCE
• FRANCE, ANATOLE (1844– )

France, See also:

• GERMANY
• GERMANY (Ger. Deutschland)

Germany, and other countries; the natural conditions were simulated by exposing heaps of decaying organic matter mixed with alkalies (See also:

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

lime, &c.) to atmospheric See also:

• ACTION

action . The salt is obtained from the soil in which it occurs naturally, or from the heaps in which it is formed artificially, by extracting with water, and adding to the See also:

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

solution See also:

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

wood-ashes or potassium carbonate . The liquid is filtered and then crystallized . Since potassium nitrate is generally more serviceable than the sodium salt, whose deliquescent properties inhibit its use for gunpowder manufacture, the latter salt, of which immense natural deposits occur (see below (2) Chile saltpetre), is converted into ordinary saltpetre in immense quantities . This is generally effected by adding the calculated amount of potassium chloride (of which immense quantities are obtained as a by-product in the See also:

• STASSFURT

Stassfurt salt See also:

• INDUSTRY (Lat. industria, from indu-, a form of the pre, position in, and either stare, to stand, or struere, to pile up)

industry) dissolved in hot water to a saturated boiling solution of sodium nitrate; the common salt, which separates on boiling down the solution, is removed from the hot solution, and on cooling the potassium nitrate crystallizes out and is separated and dried . As found in nature, saltpetre generally forms aggregates of delicate acicular crystals, and sometimes silky tufts; distinctly See also:

• DEVELOPED

developed crystals are not found in nature .

When crystallized from water, crystals belonging to the orthorhombic See also:

• SYSTEM

system, and having a See also:

• PRISM (Gr. rrpivµa, properly a thing sawn, Irpii"ety, to saw)

prism See also:

• ANGLE (from the Lat. angulus, a corner, a diminutive, of which the primitive form, angus, does not occur in Latin; cognate are the Lat. angere, to compress into a bend or to strangle, and the Gr. ayKOS, a bend; both connected with the Aryan root ank-, to

angle of 61° 1o', are obtained; they are often twinned on the prism planes, giving rise to pseudo-hexagonal See also:

• GROUPS
• GROUPS, THEORY

groups resembling See also:

• ARAGONITE

aragonite . There are perfect cleavages parallel to the See also:

• DOME (Lat domus, house; Ital. duomo, cathedral)

dome (oil) . The hardness is 2, and the specific gravity 2.1 . It is fairly soluble in water; too parts at o° dissolving 13.3 parts of the salt, and about 30 parts at 20°; the most saturated solution contains 327.4 parts of the salt in too of water; this solution boils at 114.1° . It fuses at 3390 to a colourless liquid, which solidifies on cooling to 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 fibrous See also:

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

mass, known in See also:

• PHARMACY

pharmacy as sal prunella . It is an energetic oxidizing See also:

• AGENT (from Lat. agere, to act)

agent, and on this See also:

• PROPERTY

property its most important applications depend . At a red 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 it evolves See also:

• OXYGEN (symbol 0, atomic weight 16)

oxygen with the formation of potassium nitrite, which, in turn, decomposes at a higher temperature . Heated with many metals it converts them into oxides, and with combustible substances, such as See also:

• CHARCOAL

charcoal, See also:

• SULPHUR

sulphur, &c., a most intense conflagration occurs . Its See also:

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

chief uses are in 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-making to promote fluidity, in metallurgy to oxidize impurities, as a constituent of gunpowder and in pyrotechny; it is also used in the manufacture of nitric See also:

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

acid . Potassium nitrate was used at one time in many different diseased conditions, but it is now never administered internally, as its extremely depressant action upon the See also:

• HEART
• HEART, LUNG

heart is not compensated for by any useful properties which are not possessed by many other drugs . One most valuable use it has, however, in the treatment of See also:

• ASTHMA (Gr. avBµa, gasping, whence lio-Ogaivw, I gasp for breath)

asthma . All nitrites (e.g. sodium nitrite, See also:

• ETHYL

ethyl nitrite, amyl nitrite) cause relaxation of involuntary See also:

• MUSCULAR

muscular fibre and therefore relieve the asthmatic attacks, which depend upon spasm of the involuntary muscles in the bronchial tubes .

Saltpetre may be made to See also:

• ACT (Lat. actus, actum)

act as a nitrite by dissolving it in water in the strength of about fifty grains to the See also:

• OUNCE

ounce, soaking blotting-See also:

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

paper in the solution and letting the paper dry . Pieces about 2 in. square are then successively put into a See also:

• JAR

jar and lighted . The patient inhales the fumes, which contain a considerable proportion of See also:

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

nitrogen oxides . This treatment is frequently very successful indeed in relaxing the bronchial spasm upon which the most obvious features of an attack depend . 2 . Chile saltpetre, cubic nitre or sodium nitrate, NaNO3, occurs under the same conditions as ordinary saltpetre in deposits covering immense areas in See also:

• SOUTH
• SOUTH, ROBERT (1634–1716)

South See also:

• AMERICA

America, which are known locally as caliche or terra salitrosa, and abound especially in the provinces of See also:

• TARAPACA

Tarapaca and See also:

• ANTOFAGASTA

Antofagasta in Chile . The nitrate See also:

• FIELDS, JAMES THOMAS (1817-1881)

fields are confined to a narrow See also:

• STRIP

strip of See also:

• COUNTRY (from the Mid. Eng. contre or contrie, and O. Fr. cuntree; Late Lat. contrata, showing the derivation from contra, opposite, over against, thus the tract of land which fronts the sight, cf. Ger. Gegend, neighbourhood)

country, averaging 2 M. in width, situated on the eastern slopes of the See also:

• COAST (from Lat. costa, a rib, side)

coast ranges and extending from See also:

• NORTH
• NORTH, BARONS
• NORTH, MARIANNE (1830—1890)
• NORTH, ROGER (1653-1734)
• NORTH, SIR THOMAS (1535?-16o1?)

north to south for 26o See also:

• GEOGRAPHICAL

geographical See also:

• MILES, NELSON APPLETON (1839— )

miles, between the latitudes 25° 45' and 19° 12' S . The nitrate forms beds, varying in thickness from 6 in. to 12 ft., under a covering of See also:

• CONGLOMERATE (from the Lat. conglomerare, to form into a ball, glomus, glomeris; so also the general term " conglomeration " for a miscellaneous collection of things, gathered together in a mass)

conglomerate locally known as lostra, which is itself overlain by a loose sandy soil . The conglomerate consists of See also:

• ROCK
• ROCK (O.Fr. rake, Sp. rota, Ital. rocca; possibly from a Lat. form rupica, from rupes, rock)
• ROCK, DANIEL (1799–187t)

rock fragments, sodium chloride and various sulphates, cemented together by See also:

• GYPSUM

gypsum to See also:

• FORM (Lat. forma)

form a hard compact mass 6 to to ft. in thickness . The caliche has often a granular structure, and is yellowish-white, See also:

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

bright See also:

• LEMON
• LEMON, MARK (1809-1870)

lemon-yellow, brownish or See also:

• VIOLET

violet in See also:

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

colour . It contains from 48 to 75% of sodium nitrate and from 20 to 40% of common salt, which are associated with various See also:

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

minor saline components, including sodium iodate and more or less insoluble See also:

• MINERAL

mineral, and also some organic matter, e.g. See also:

• GUANO (a Spanish word from the Peruvian huanu, dung)

guano, which suggests the See also:

• IDEA (Gr. Ibia, connected with i&eiv, to see; cf. Lat. species from specere, to look at)

idea that the nitrate was formed by the nitrification of this See also:

• KIND (O. E. ge-cynde, from the same root as is seen in " kin," supra)

kind of excremental matter . The caliche is worked up in loco for crude nitrate by extracting the salts with hot water, allowing the suspended See also:

• EARTH
• EARTH (a word common to Teutonic languages, cf. Ger. Erde, Dutch aarde, Swed. and Dan. jord; outside Teutonic it appears only in the Gr. 'pq'e, on the ground; it has been connected by some etymologists with the Aryan root ar-, to plough, which is seen in
• EARTH, FIGURE OF
• EARTH, FIGURE OF THE

earth to See also:

• SETTLE
• SETTLE, ELKANAH (1648–1724)

settle, and then transferring the clarified liquor, first to a cistern where it deposits See also:

• PART

part of its sodium chloride at a high temperature, and then to another where, on cooling, it yields a See also:

• CROP (a word common. in various forms, such as Germ. Kropf, to many Teutonic languages for a swelling, excrescence, round head or top of anything; it appears also in Romanic languages derived from Teutonic, in Fr. as troupe, whence the English " crupper "

crop of crystals of purified nitrate .

The nitre thus refined is exported chiefly from See also:

• VALPARAISO

Valparaiso, whence the name of " Chile saltpetre." The See also:

• MOTHER

mother liquors used to be thrown away, but are now utilized for the extraction of their See also:

• IODINE (symbol I, atomic weight '26.92)

iodine (q.v.) . Chemically pure sodium nitrate can be obtained by repeated recrystallization of Chile saltpetre or by See also:

• SYNTHESIS (Gr. a6vOeacs, from avvrcBivac, to put together)

synthesis . It forms colour-less, transparent rhombohedra, like those of See also:

• ICELAND (Dan. Island)

Iceland spar; the angles are nearly equal to right angles, being 73° 30', so that the crystals look like cubes: hence the name of " cubic saltpetre." There are perfect cleavages parallel to the See also:

• RHOMBOHEDRAL

rhombohedral faces, and the crystals exhibit a strong negative 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 See also:

• REFRACTION
• REFRACTION (Lat. refringere, to break open or apart)

refraction, like See also:

• CALCITE

calcite . One See also:

• HUNDRED

hundred parts of water at o° and at too° dissolve 72.9 and 18o parts of the salt; at 120° the boiling-point of the saturated solution, 216 parts . The salt fuses at 316°; at higher temperatures it loses oxygen (more readily than the corresponding potassium salt) with the formation of nitrite which, at very high temperatures, is reduced ultimately to a mixture of peroxide, Na202, and See also:

• OXIDE

oxide, Na2O . The chief applications of Chile saltpetre are in the nitric acid industry, and in the manufacture of ordinary saltpetre for making gunpowder, ordinary Chile saltpetre being unsuitable by See also:

• REASON (Lat. ratio, through French raison)

reason of its deliquescent nature, a property, however, not exhibited by the perfectly pure salt . It is also employed as a manure . For references to See also:

• MEMOIRS

memoirs See also:

• SALUTATIONS, or GREETINGS

SALUTATIONS descriptive of the Chilian nitrate deposits, see G . P . See also:

• MERRILL

Merrill, The Non-Metallic Minerals (New See also:

• YORK
• YORK (HOUSE OF)
• YORK, EDMUND OF LANGLEY, DUKE OF (1341-1402)
• YORK, EDWARD
• YORK, FREDERICK AUGUSTUS, DUKE OF (1763-1827)
• YORK, RICHARD, DUKE

York, 1904) . 3 . Wall-saltpetre or lime saltpetre, calcium nitrate, Ca(NO2)2, is found as an efflorescence on the walls of stables; it is now manufactured in large quantities by fixing atmospheric nitrogen, i.e. by passing a powerful electric arc See also:

• DISCHARGE (adapted from the O. Fr. discharge, modern decharge, from a med. Lat. discargare, to unload, dis- and earn care, to load, cf. " charge ")

discharge through moist air and absorbing the nitric acid formed by lime .

Its chief applications are as a manure and in the nitric acid industry .