N I C

N I C

( 135 )

tiling certain is known. It is found in China and India, in Switzerland , Piedmont and Tyrol.

It is difficult to faw or cut, and even whenpolifhed has a muddy appearance : its greattoughncfs however enables the artift to fafhionit into works of great delicacy. It is muchprized by the Hindoos and Chinefe, by whomit is made into talifmans and idols, and by the.Turks, who fortn it into fword and daggerhandies.

2. Suhfp. Axeftone. BeilJfein,'SNe rn. Pierrede IIache, Broch.

Its colour varies between deep bluifh andyellowilh green, and fometimes pafles into olive.It occurs in rnafs: internally it is ftrongly glif-tening with fomewhat of a refinous luftre. Its'fradture in the great is flaty, and in the fmall,fplintery. Its fragments arc tabular. It istrar.fiucent, and in hardnefs and tcsughnefs ap-proaches nearly to the preceding fubfpecies.

Its natural fituation appears to be in beds ofargillaceous fchiftus.

It occurs in South America, in New Zealand and other ifiands of the Pacific ocean , where itis made by the natives into hatchets, tomahawksand other inftruments. It is alfo found inCorfica, Switzerland and Saxony .

Nephrite appears to be clofely connected withv.'hetftone Hate and indurated talc.

NEUTRAL SALTS. See Salts.

NICKEL. Nikkei, Germ, Nikel , Fr.

Nickel is a yellowilh white fcmi-malleablemetal, difficultly fufible, attradUble by the mag-net, ibluble in nitric acid to which it gives agreen colour, and when in the Hate of ox'yrf,'ioluble in ammonia, to which it gives a Lluecolour.

§. I. Ores of Nickel.

Sp. i. Copper Nickel. Ktipfer Nikkei, Wern.

Its colour is pale copper red with a yellowilhor greyifh tint. It occurs mallive and diflemi-nated, fometimes though rarely reticular, arbo-refcent or botryoidal. It is more or lefs ffiining■with a metallic luftre. Its fradture is imper-fectly conchoidal, paffing into coarfe graineduneven (this latter variety pofleffes the leaf! luf-Its fragments are indeterminately angularr,,- 31 ? e< % e< f- It fometimes occurs in granular.

lamellar diftindt concretions. Its

or

fteel,arfenical

i ? ur '[ e<; I lamellar diitmdt concretions.

C 06 j%' S con fiderable for it gives fire withuengaging at the fame time a ftrong

r.„ •], ° d c ° Ur ' It is brittle, but difficultly

frangible. Sp. gr . 6 .6. ’ ;

Before the blowpipe it gives out an arfenicalvapour, and then fufes though not very eafilyinto a dark fcoria mixed with metallic grains.

It appears to confift eflentially of nickel andarfenic, but it alfo contains fulphur, iron, co-balt, copper, and not unfrequently bifmuth anclfilver.

It occurs in veins both in primitive and ftra-tified mountains accompanied by various oresof cobalt and filver, and by heavy fpar, calcareousfpar, brown fpar, and quartz.

It is found moll abundantly at Joachimflhal’in Bohemia , Schneebtrg, Freyberg and Anna-berg in Saxony ; and Andreafberg in the Hartz;it is alfo rfiet with in Cornwall in England, atAllemont in France , in Stiria, in Arragon inSpain, and Kolywan in Siberia .

Sp. 2. Nickel Ochre. Nikkei Okhr, Wern.

Its ufual colour is apple green, paffing tografs-green and greenifh white; when moiftthe colour is confiderably deepened. It occursdiffeminated, and as a fuperficial covering oncopper nickel and the ores of cobalt. It iscompofed of loofe or flightly cohering pulveru-lefnt particles. It is meagre to the touch and islight. ■

It is infufible per fe by the blowpipe, whenmelted with borax this latter acquires a hya-cinthine colour and metallic globules are pro-duced. It is often in part foluble in water, butthis arifes from an admixture of fulphat ofnickel, which may thus be feparated from tireproper ochre.

It is found in the fame places and fituationsas the preceding fpecies.

§ 2. Analysis of Ores.

Copper nickel though not confiding eflentiallyof more than two or three ingredients may yetcafually. contain a confiderable variety of otherfubltances as has been fhown above. In'givingtherefore a formula for its analyfis it will beadvifable to confider it. in its moft compoundform. Hence we fliall fuppofe it to containnickel, arfenic, fulphur, copper, iron, cobalt,filver, and bifmuth, befides quartz and alumine.

1. The ore being ground to an impalpablepowder niuft be digefted with nitric acid con-liderably diluted, nitrous gas will be given out,and by two or three digeftions every thing folu-ble will be taken up.

2. The infoluble portion, confifting for themoft part of fulphur and filex, is to be dried,weighed, and then heated •, the fulphur (a) willburn off, and its amount may be afcertained bythe difference of weight before and after ig-nition. The refidue after being boiled in a.little nitrous acid is pure filex (b).

3. Add together both the nitrous folutionsnearly faturate the liquor with pure foda, eva-