pipe it melts without frothing into a white femitransparent glass.

GENUS XII. iv. SLA. Sp. 9. LAZULITE. This ftone, which is found chiefly in the northern parts of Afia, has been long known to mineralogifts by the name of Lapis Lazuli." (See LAZULI.) "This term has been contracted into Lazulite by M. Hauy; an alteration which was certainly proper. Lazulite is always amorphous. Its texture is earthy; fracture uneven; luftre opaque, or nearly fo; hardness 8 to 9; fp. gravity 276 to 2945; colour blue, often fpotted white from specks of quartz, and yellow from particles of pyrites. It retains its colour at 100° Wedg, in a higher heat it intumefces, and melts into a yellowith black mass. With acids it effervefces a little; and, if previously calcined, forms with them a jelly. MARGRAFF published an analyfis of lazulite in the Berlin Mem. for 1758. It has been fince confirmed by Klaproth, who found a fpecimen of it to contain 46 filica, 14'5 alumina, 28 carbonat of lime, 6'5 fulphat of lime, 3 oxide of iron, and 2 water. From MORVEAU's experiments it appears, that the colouring matter of lazulite is fulphuret of iron. The name is from the Arabian word azul, blue.

"GENUS XIII. SALE.

66

Sp. 1. GARNET. This ftone is found abundantly in many mountains." (See GARNET and GRANATE.) It is ufually cryftallized. The primitive form of its crystals is a dodecahedron, whofe fides are rhombs, with angles of 78° 31' 44", and 120° 28' 16". The inclination of the rhombs to each other is 120°. This dodecahedron may be confidered as a four-fided prifm, terminated by four-fided pyramids. It is divifible into 4 parallelopipeds, whofe fides are rhombs; and each of these may be divided into 4 tetrahedrons, whofe fides are ifofceles triangles,, equal and fimilar to either of the halves into which the rhomboidal faces of the dodecahedron are divided by their shorter diagonal. The integrant molecules are fimilar tetrahedrons. Sometimes the edges of the dodecahedron are wanting, and fmall faces in their place; and fometimes garnet is cryftallized in polyhedrons, having 24 trapezoidal faces. (See Rome de Lille ii, 322, and Hauy Anz.de Chim.xvii.) The texture of garnet, as BERGMAN firft fhowed, is foliated; its fracture commonly conchoidal; internal luftre from 4 to 2; tranfparency 2 to 4; fometimes only 1 or o; caufes fingle refraction; hardnefs from 10 to 14. Specific gravity 3'75 to 4'188. Colour ufually red; often attracted by the magnet; fufible per fe by the blow-pipe.

"Var. 1. Oriental Ġarnet, supposed to be the Carbuncle (ayiga) of Theophraftus. Internal luftre 3 to 4; transparency 4; hardness 13 to 14; fpecific gravity 4 to 4'188. Colour deep red, inclining to violet.

“Var. 2. Common Garnet. Fracture uneven, inclining to the conchoidal. Internal luftre 2 to 3; transparency 3 too; hardnefs to to 11, fometimes only 9; fpec. gravity 3'75 to 4. Colour deep red inclining to violet; fometimes verging towards black or olive; fometimes leck green, brown, yellow.

"Var. 3. Amorphous Garnet. Structure flaty;

luftre 2; tranfparency 2 to 1; hardness It to 12; fpecific gravity 3.89. Colour brownish or blackish red. Found in Sweden, Switzerland, and the Eaft Indies.

"A fpecimen of oriental garnet, analysed by Klaproth, contained 35°75 filica, 27:15 alumina, 36 oxide of iron, and o°25 oxide of manganefe. A fpecimen of red garnet, analyfed by Vauquelin, contained 52 filica, 20 alumina, 17 oxide of iron, 77 lime.

66

Sp. 2. PYROP. This mineral, which is found in Saxony and Bohemia, has been lately separated from the garnet by Werner, and made a distinct fpecies. It is never found cryfta'lized, but only in round or angular fragments, ufually fmall. Colour deep red, (hence the name, ug), which paffes to orange when exposed to the fun. Very hard. Specific gravity unknown. Fracture conchoidal and very brilliant.

"Sp. 3. MELANITE. This mineral was formerly confounded with the garnet. It is found at Frafcati in Italy, ftuck in lava. It is of a black colour, and crystallized like the garnet in a dodecahedron, having its edges truncated. It was analyfed by Vauquelin, and yielded 43 filica, 16 alumina, 20 lime, 16 oxide of iron, and 4 moif

ture.

It is

"Sp. 4. THUMMERSTONE. Yanolite of La Metherie: Axinite of Hauy. This tone was first defcribed by SCHREBER, who found it near Balme d'Auris, in Dauphine, and named it Shorl violé. It was afterwards found near Thum in Saxony; whence Werner called it Thummerstone. fometimes amorphous; but more commonly cryftallized. The primitive form of its crystals is a rectangular prifm, whofe bafes are parallelograms, with angles of 101° 32′ and 78° 28'. The most ufual variety is a flat rhomboidal parallelopiped, with two of its oppofite edges wanting, and a small face instead of each. The faces of the parallelopiped are generally streaked longitudinally. The texture of thummerftone is foliated; its fraċture conchoidal; luftre 2; transparency, when cryftallized, 3 to 4; when amorphous, 2 to 1. Caufes fimple refraction; hardness 10 to 9; fpecific gravity 3'2956. Colour clove brown; fometimes inclining to red, green, grey, violet, or black. Before the blow-pipe it froths like zeolite, and melts into a hard black enamel. With borax it exhibits the fame phenomena, or even when fimply heated at the end of a pincer. A fpecimen, analyfed by Klaproth, contained 52°7 filica, 25*6 alumina, 9'4 lime, and 9'6 oxide of iron. A fpecimen, analysed by Vauquelin, contained 44 filica, 18 alumina, 19 lime, 14 oxide of iron, and 4 oxide of manganefe.

"Sp. 5. PREHNITE. Though this stone had been mentioned by SAGE, Rome de Lifle, and other mineralogifts, Werner was the rft who properly distinguished it from other minerals, and made it a diftinct fpecies. The ipecimen which he examined was brought from the Cape of Good Hope by Col. PREHN; hence the name. It was found near Dunbarton by Mr GROTCHE; and has fince been obferved in other parts of Scotland. It is both amorphous and cryftallized. The cryfais are in groups, and confufed: they feem to be four

chemift, contained 10'15 oxide of iron, 41'15 filica, 613 alumina, 39'47 magnefia, 1'5 lime, 15 air and water. On the fuppofition, that thefe analyfes are accurate, the enormous difference between them is a demonstration, that chlorite is not a chemical combination, but a mechanical mixture. "GENUS XVI. SLAM.

"Sp. 1. SILICEOUS SPAR. This stone has been found in Tranfylvania. It is cryftallized in four or fix-fided prifms, channelled tranfverfely, and generally heaped together. Its texture is fibrous: Luftre filky, 2: Colours white, yellow, green, light blue. According to BINDHEIM, it contains 611 filica, 217 lime, 6·6`alumina, 5 magnefia, 1'3 oxide of iron, 3'3 water." See SPAR.

"GENUS XVII. SAMLI.

Sp. 1. ARGILLITE. Argillaceous Shiftus. Common SLATE. This ftone conftitutes a part of many mountains. Its ftructure is flaty: texture foliated: Fracture splintery: Fragments often tabular: Luftre moft commonly fiiky, 2; fometimes o: Tranfpa rency from o to 1: Hardness from 5 to 8. Specific gravity from 2'67 to 2:88: Does not adhere to the tongue : gives a clear found when struck: often imbibes water: Streak white or grey: Colour most commonly grey, with a fhade of blue, green or black; fometimes purplish, yellowish, mountain green, brown, bluish black; fometimes ftriped or spotted with a darker colour than the ground. It is compofed, according to Kirwan, of filica, alumina, magnefia, lime, oxide of iron." (See SCHISTUS.) "In fome varieties the lime is wanting. Several varieties contain a confiderable quantity of carbonaceous matter. See SLATE.

"GENUS XVIII. SLACMI. "Sp. 1. SMARAGDITE. This ftone was called Smaragdite by M. Sauffure from fome resemblance it has to the emerald. Never cryftallized: Texture foliated: eafily divided into plates: Laminæ inflexible: Fracture even: Hardness 7: Spec. gravity 3 Colour in some cases fine green; in others it has the grey colour and metallic luftre of mica: It affumes all the fhades between these two extremes. According to Vauquelin, it is compofed of so parts filica, 13 lime, 11 alumina, 7'5 oxide of chromum, 6 magnefia, 5°5 oxide of iron, 1'5 oxide of copper.

"GENUS XIX. SM. "Sp. 1. KIFFEKIL. MYRZEN. SEA-FROTH, This mineral is dug up near Konie in Natolia, and employed in forming the bowls of Turkish tobacco pipes. The fale of it fupports a monaftery of Dervifes established near Konie. It is found in a large fiffure 6 feet wide, in grey calcareous earth. The workmen affert, that it grows again in the fiffure, and puffs itself up like froth. Hence the name kiff-kill, or rather keff-kelli, clayfroth, or light clay. This mineral, when fresh dug, is of the confiftence of wax; it feels soft and greafy; its colour is yellow; its fpecific gravity 16; when thrown on the fire it fweats, emits a fetid vapour, becomes hard, and perfectly white. According to Klaproth, it is compofed of 50's filica, 1725 magnefia, 25 water, 5 carbonic acid, and o's lime.

**Sp. 2. STEATITES. Though this mineral was

noticed by the ancients, little attention was paid to it by mineralogifts, till Mr Porr published his experiments on it, in the Berlin Memoirs for 1747. It is ufually amorphous, but fometimes cryftallized in fix-fided prifms. Its texture is commonly earthy, but fometimes foliated; Luftre from 0 to 2; Hardness 4 to 7; Spec. gravity from 2:61 to 2'794; Feels greafy; Seldom adheres to the tongue; Colour ufually white or grey; often with a tint of other colours; the foliated commonly green; does not melt per fe before the blow-pipe.

"Var. 1. Semi-indurated Steatites. Texture earthy; Fracture fometimes coarse splintery; Luftre o Transparency o, or scarce 1; Hardness 4 to 5; Abforbs water; takes a polish from the nail; Colour white, with a shade of grey, yellow or green; fometimes pure white; fometimes it contains dendritical figures; and fometimes red veins.

"Var. 2.

Indurated Steatites. Fracture fine fplintery; often mixed with imperfectly conchoidal. External luftre 2 to 1; internal o; Tranfparency 2; often has the feel of foap; Abforbs water; Colour yellowish or grey; often veined or fpotted with deep yellow or red.

"Var. 3. Foliated or Striated Steatites. The texture of this variety, is usually foliated; fometimes ftriated; Fragments cubiform; Luftre 3; Tranfparency 2 to 1; Hardness 6 to 7; Colour leek green, paffing into mountain green or fulphur yellow: Streak pale greenish grey. When heated to redness, it becomes grey; and at 147° Wedg. forms a grey porous porcelain mass.

"A fpecimen of Steatites, analyfed by Klaproth, contained 59°5 filica, 30's magnefia, 2'5 iron, and s's water. A fpecimen of white fteatite, analysed by M. Chenevix, contained 60 filica, 28'5 magnefia, 3 alumina, 2'5 lime, 2.25 iron. "GENUS XX. Ms1.

Sp. 1. CHRYSOLITE. Peridot of the French. Topaz of the ancients. The name Chryfolite was applied, without difcrimination, to a great variety of ftones, till Werner defined it accurately, and confined it to that which the French chemifts diftinguish by the appellation of peridot. This ftone is the TOPAZ of the ancients; their chryfo. lite is now called topaz. Chryfolite is found fometimes in unequal fragments and fometimes cryftallized. The primitive form of its crystals is a right angled parallelopiped, whose length, breadth, and thickness, are as 5, 8, 5. The texture is foliated; Fracture conchoidal; internal luftre from 2 to 4. Tranfparency 4 to 2; Caufes double refraction; Hardness 9 to 10; Brittle. Specific gravity from 3'265 to 3°45; Colour green. It is infufible at 150°, but lofes its transparency, and becomes blackish grey. With borax it melts without effervefcence into transparent glass of a light green colour. Infufible with microcosmic falt and fixed alkali.

"Var, 1. Common Chryfolite; Found in Ceylon, S. America and Bohemia, amidst fand and gravel; Luftre 3 to 4; Transparency 3 to 3; Colour yel lowish green, fometimes verging to olive green, fometimes to pale yellow.

"Var. 2. Olive Chryfolite. Olivine of Kirwan. Found commonly among traps and bafalts; fometimes in fmall grains, fometimes in pretty large

pieces;

pieces; but it has not been obferved in crystals: Luftre 2 to 3: Transparency 3 to 2: Colour olive green.

"The ft variety, according to Klaproth, is compofed of 415 magnefia, 38.5 filica, and 19 oxide of iron. According to Vauquelin, it is compofed of 51'5 magnefia, 38 filica, and 9'5 oxide of iron. The 2d variety, according to Klaproth, is compofed of 3758 magnefia, so filica, 11*75 oxide of iron, o'21 lime.

"Sp. 2. JADE. This ftone was formerly called lapis nephriticus, and was much celebrated for its medical virtues." (See JADE, § 2, and LAPIS, N° 17.) "It is found in Egypt, China, America, and in the Siberian and Hungarian mountains; fometimes adhering to rocks, and fometimes in detached round pieces. Its furface is fmooth; Fracture splintery: External luftre o, or fcarce : Hardnefs 10 Not brittle: Spec. gravi. ty from 2'95 to 2'9829; or according to Sauffure, to 3 389: Feels greafy: Looks as if it had im. bibed oil: Colour dark leek green, or verging towards blue: in fome prominencies inclining to greenish or bluish white. When heated it becomes more tranfparent and brittle, but it is infufible per fe. According to HOEPFNER, it is compofed of 47 parts filica, 38 carbonat of magnefia, 9 iron, 4 alumina, and 2 carbonat of lime. This is the ftone which the inhabitants of New Zealand make into hatchets and other cutting inftruments.

"GENUS XXI. SML.

"Sp. 1. ASBESTUS. This mineral was well known to the ancients." (See ASBESTOS.) They even made a kind of cloth from one of the varieties, which was famous for its INCOMBUS TIBILITY. It is found abundantly in moft mountainous countries, and no-where more abundantly than in Scotland. It is commonly amorphous; Texture fibrous; fragments often long fplintery; Luftre from o to 2; fometimes 3, and then it is metallic; Tranfparency from o to 2; Hardness from 3 to 7 Spec. gravity from 27 to 06806; Abforbs water; Colour ufually white or green; fufible per fe by the blow-pipe.

"Var. I. Common Afbeftus. Luftre 2 to 1; Transparency 1; Hardness 6 to 7: Specific gravity 2'577 to 27. Feels fomewhat greafy; Colour leek green; fometimes olive or mountain' green; fometimes greenish or yellowish grey; Streak grey; powder grey.

"Var 2. Flexible Afbeftus. Amiantus. Compofed of a bundle of threads flightly cohering." (See AMIANTHUS.) "Fibres flexible; Luftre 1 to 2, fometimes 3; Transparency 1 to 2, fometimes o; Hardnefs 3 to 4; Spec. gravity before it absorbs water, from o'9088 to 2'3134; after abforbing water, from 15662 to 2.3803. Feels greafy; Colour greyish or greenish white; fometimes yellowish or filvery white, olive or mountain green, pale flesh red, and mountain yellow.

"Var. 3. Elaftic Afbeftus. Mountain Cork. This variety has a strong resemblance to common cork. Les fibres are interwoven. Luftre commonly o; Opaque; Hardness 4; Spec. gravity, before abforbing water from o'6805 to 09933; after it, from 1*2492 to 1°3492. Feels meagre; Yields to the fingers like cork, and is fomewhat elastic. Co

lour white; fometimes with a fhade of red or yellow; fometimes yellow or brown.

"A fpecimen of the 1ft variety from Dalecarlia, analysed by Bergman, contained 63°9 filica, 16 carbonat of Magnefia, 12'8 carbonat of lime, 6 oxide of iron, 11 alumina. A fpecimen of 2d var. yielded 64 filica, 172 carbonat of magnesia, 13°9 carbonat of lime, 29'7 alumina, and 22 oxide of iron. A fpecimen of 3d var. contained 56°2 filica, 26'1 carbonat of magnefia, 12°7 carbonat of lime, 3 iron, and 2 alumina. Twelve different specimens of afbeftus, analyfed by BERGMAN, yielded the fame ingredients, differing a little in their proportions.

"Sp. 2. ASBESTINITE. This ftone is amor. phous; Texture foliated or broad ftriated; Luftre filky, 3; Tranfparency 1 to 2; Hardness 5 to 6; specific gravity from 2·806 to 2'880. Colour white, with fhades of red, yellow, green or blue. At 150° Wedg. it melts into a green glass.

GENUS XXII. i. SILM.

"Sp. 1. AUGITE. PYROXEN of Hauy. VoDCANITE of De La Metherie. This mineral is only found in bafait and lava. It is usually in grains, or in small cryftals. The primitive form of its cryftals is an oblique angled prifm, whofe bafes are rhombs with angles of 92° 18 and 37° 42'. It generally cryftallizes in fix or eight-fided prifms, terminated by dihedral fummits. Its texture is foliated; Hardness 9; Fracture imperfectly conchoidal and brilliant; ufually fomewhat transparent. Colour deep green, or greenish black; powder greenish grey; Sp. gravity 3'47; Commonly attracted by the magnet; fcarcely fufible by the blow-pipe; With borax it melts into a yellowish glafs, which appears red while it is hot. According to Vauquelin's analyfis, it is compofed of 52 parts filica, 14'66 oxide of iron, 13'2 lime, to magnefia, 3°33 alumina, and 2 oxide of manganefe.

"Sp. 2. ASBESTOID. This ftone has obtained its name from its fimilarity to common asbestus. It is amorphous; its texture is foliated or flriated; its luftre common or glaffy, from 2 to 3 ; Transparency from 0 to 1; Hardness 6 to 7; Specific gravity from 3 to 3*31; Colour olive or leek green; when decompofing, brown. Before the blow-pipe it melts per fe into a brown globule, With borax it forms a violet-coloured globule, verging towards hyacinth. According to MacQUART'S analyfis, it is compofed of 46 filica, 20 oxide of iron, 11 lime, 10 oxide of manganese, and 8 magnefia.

"There is a variety which Kirwan calls Metalliform Afbeftoid. Its luftre is semi-metallic, 3i Opaque; Hardness 8 to 9; Spec. gravity 3*356; Colour grey, fometimes inclining to red.

"GEN. XXII. . SMIL. Species 3. SHORLACEOUS ACTINOLITE. Rayonnante. This stone cryftallizes in four or fix-fided prifms, thicker at one end than the other; hence it has been called by the Germans firahlftein, i. e. arrow-flone. The cryf tals sometimes adhere longitudinally. Fracture hackly; External luftre glafly, 3 to 4; internal to 2; Tranfparency 2 to 3; fometimes I ; Hardnefs 7 to 10; Sp. gravity 3'023 to 3'45. Colour leek or dark green. This ftone is often the ma trix of iron, copper, and tin ores.

“Sp. 4. Lamellar Actinolite. This ftone refembles hornblende. It is amorphous: texture foliated: Luftre various in different places: Transparency o, or scarce 1: Sp. gravity 2'916: Colour dark yellowish, or greenish grey.

"Sp. 5. Glaffy Adinolite. This ftone is found amorphous, composed of fibres adhering longi. tudinally, or in flender four or fix-fided prifms: Texture fibrous: Fragments long fplintery, fo fharp that they can scarcely be handled: external luftre glafly or filky, 3 to 4; internal o: Tranfparency 2: Exceedingly brittle. Specific gravity 2'95 to 3493: Colour leek green; fometimes verging towards greenifh or filver white; fometimes ftained with yellowish or brownish red. According to Bergman it is compofed of 72 filica, 127 carbonat of Magnefia, 6 carbonat of lime, 7 oxide of iron, and 2 alumina.

"Sp. 6. IDOCRASE. Hyacinthine of De la Metherie. Sorlo Picéo of GIOENI. This mineral is found in lava, and was formerly confounded with the hyacinth. Its colour is brown or greenifh, and it is usually cryftallifed in rectangular eightfided prifms, or rather four-fided prifms with their edges truncated. The primitive form of its cryftals is the cube. Spec. gravity from 3°39 to 3'409. Scratches glafs: Luftre 2: Fracture imperfectly conchoidal: Transparent: Caufes double refraction. Before the blow-pipe melts into a yellowifh glaís. According to STUCKE's analyfis, it is compofed of 265 filica, 40°2 magnefia, 16°2 oxide of iron, and 16 lime.

"GENUS XXIII. SL.

"Sp. 1. SHISTOSE HORNSTONE. The ftructure of this stone is flaty: Luftre from o to 1: commonly opaque: Hardness 9 to 10: Specific gravity from 2'596 to 2'641: Colour dark bluish or blackish grey: Infusible per fe.

"Var. 1. Siliceous fhiftus. Commonly interfected by reddish veins of iron ftone: Fracture splintery: Luftre o: Transparency from o to 1.

"Var. 2. Bafanite, or Lydian Stone. Commonly interfected by veins of quartz: Fracture even; fometimes inclining to conchoidal: luftre fcarce 1: Hardness 10: Spec. gravity 2'596: Powder black: Colour greyish black. This, or a ftone fimilar to it, was used by the ancients as a TOUCHSTONE. They drew the metal along the ftone, and judged of its purity by the colour of the metallic ftreak. On this account they called it Barava, the trier." See LYDIUS LAPIS.

"A fpecimen of the first variety, analysed by Wiegleb, contained 75 parts filica, 10 lime, 4'6 magnesia, 3'5 iron, and 5°2 carbon. This fpecies is rather a mechanical mixture, than a chemical combination.

"Sp. 2. TREMOLITE. This mineral, found in the valley of Tremola in the Alps, has been defcribed by Sauffure, and feems to be very intimately connected with the minerals arranged under the ad divifion of the laft genus. It is white, with a fhade of green or red, and is either cryftallized or in irregular maffes. Its cryftals are four-fided oblique prifms, with angles of 67° and 113. Sp. gravity from 2'9 to 32: Texture fibrous: Fracture conchoidal: Fibres rigid, fo that it irritates the skin when rubbed againft it: Cuts glafs. Luftre confiderable: fomewhat transparent. VOL. XV. PART L

Fibres eafily feparated, fo that it appears foft. Phosphorefces when two pieces are rubbed in the dark against each other. VON BERCHEN and STRUVE have divided this fpecies into 3 varieties: namely the common, glassy, afbeftiform, filky, and grey. A fpecimen analysed by Klaproth contained 65 parts filica, 38 lime, 0'5 magnesia, o'g oxide of iron, and 6 water and carbonic acid.

"GENUS XXIV. Zs.

"Sp. 1. ZIRCON. Jargon. Hyacinth. This ftone is brought from Ceylon, and found alfo in France, Spain, and other parts of Europe. It is commonly cryftallized. The primitive form of its cryftals is an octahedron, composed of 2 fourfided pyramids, applied bafe to bafe, whofe fides are ifofceles triangles. The inclination of the fides of the same pyramid to each other is 124° 12′: that of the fides of one pyramid to those of another 82° 50'. The folid angle at the apex is 73° 44'. The varieties of the cryftalline forms of zircon amount to 7. In fome cafes there is a fourfided prifm interpofed between the pyramids of the primitive form; fometimes all the angles of this prifm are wanting and two small triangular faces in place of each; fometimes the crystals are dodecahedrons, compofed of a flat four-fided prifm with hexagonal faces, terminated by four-fided fum mits with rhomboidal faces; fometimes the edges of this prifm, fometimes the edges where the prifm and fummit join, and sometimes both are wanting and small faces are in their place. The texture of Zircon is foliated: Internal luftre 3: Tranfparency from 4 to 2. Caufes a very great double refraction: Hardness from 10 to 16: Sp. gravity from 42 to 4 165: Colour commonly reddish or yellowish; fometimes it is limpid. Before the blowpipe, it loses its colour, but not its transparency With borax it melts into a transparent glass. Infufible with fixed alkali and microcosmic falt.

"1. The Variety, formerly called hyacinth, is of a yellowish red colour, mixed with brown. Its furface is fmooth: luftre 3 Transparency 3 to 4." (See HYACINTH, N° 5.).

"2. The Variety, formerly called Jargon of Ceylon, is either grey, greenifh, yellowish brown, reddish brown, or violet. It has little external luftre. It is fometimes nearly opaque.”—See CHEMISTRY, Index; and JARGON, N° 2.

"The firft variety, according to Vauquelin, is compofed of 64'5 zirconia, 32 filica, and 2 oxide of iron. A fpecimen, analysed by Klaproth, con tained 70 zirconia, 25 filica, and o's oxide of iron. The 2d variety, according to Klaproth, who difcovered the component parts of both, contains 68 zirconia, 31°5, filica, and o°5 nickel and iron. GENUS XXV. Ys1.

"GADOLINITE. This mineral was first observed by Capt. ARHENIUS, lodged in a white felspar in the quarry of YTTERBY in Sweden, and received the name of Gadolinite, because GADOLIN was the chemift, who first ascertained its compo fition. It occurs in thick kidney-form maffes, or, in parallel plates. Its colour is black; that of its powder greenifh grey: Fracture conchoidal and glaffy: Opaque: Scratched by iron, and in fome cafes even by the nail. Attracted by the magnet. Before the blow-pipe decrepitates and melts into a black blistered flag: Forms with borax a yellowG

ifh