NI C
( 138 ) NIT
pofing the falts of nickel: even zinc, althoughaflifted by an excefs of muriatic acid in the folu-tion, and a boiling-temperature, has no effect onthe fait when the nickel is pure : a mud-colouredprecipitate indeed is not unfrequently depofitedfrom the folution of common nickel, but this pre-cipitate is for the moll part arfenic and iron, withwhich nickel purified in the ufual way alwaysabounds. Hence it is that in proportion to theaction of the zinc on this compound fait, thegreen colour of the folution becomes more andmore pure and bright; and when all the arfeniccapable of precipitation by this method hasfallen down, no further digeftion with zinc orany other metal will produce the leaft effedt.
There are no experiments on the combinationof pure nickel with fulphur or phofphorus, butas the common regulus unites without difficultywith thefe combultibles it is probable that thepure metal will do fo likewife.
The alloys of nickel with the other metalshave been but little examined.
When combined with gold in the proportionof three or four grains of the former to an ounceof the latter, neither the colour nor malleabilityof the mafs materially differs from that of puregold, but if the proportion of nickel amounts to2o grains of alloy in the ounce, the refult is amixture of a brafs colour, a coarfe grain, andvery brittle. f
With filver it may be combined accordingto Bergman, in nearly equal proportions, withoutimpairing in any remarkable degree either thecolour or duftility of the filver.
With copper it forms an alloy of lefs du&ilitythan pure copper, and the magnetic quality ofthe nickel is diminifhed though by no meansdeftroyed.
With tin it forms a white brittle compound.
By mixture with arfenic it forms a brittle andeafily fufible mafs, entirely incapable of beingadled on by the magnet. If the proportion ofarfenic in the compound is con'fiderable, it willemit fumes of this metal by expofure to the blow-pipe, and if it be broken to pieces and roafted at alow red-heat it will be covered with a green arbo-refcence of arfenicated oxyd of nickel: by arepetition of alternate roaltings and reductionswith a carbonaceous flux, the arfenic may be fofar feparated as that the alloy will give out nomore vapours, nor produce any arborefcence,after which by repeated fcorification with nitre,the remaining arfenic may be almoft entirely gotrid of; but this method is neither fo expeditious
or fatisiactory as that already detailed in thepreceding fe£lion.
Nickel and iron feem to unite together in allproportions : the colour of the alloy approachesmore to that of filver, as the nickel prevails init; and its ductility and power of magnetifmappear to be fully equal to that of pure iron.It is remarkable that all the fpecimens of mete-oric iron that have been analyfed, are naturalalloys of iron and nickel, of which this latterconftitutes from 1.5 to 17. per cent. Thefemaffes differ from pure iron in being fcareelyat all oxydable by expofure to the weather, it ishighly probable therefore that nickel may be-come a metal of vail importance if its power ofprotecting iron from ruff be fully eftablifhed.
Oxyd of nickel is foluble by fufion .in variousvitrefcent mixtures, to which it gives differenttinges of colour according to the nature of thefaline ingredient made ufe of as a flux.
A mixture of Pure filiceous earth 80 grains,Carbonated potafli 60Oxyd of nickel - 3
affords by fufion a hard clear violet-blue glafs. e
Siliceous earth - 60
Calcined borax - 60Oxyd of nickel - 3
yield a glafs of a clear brown with a tinge ofblue, or a hyacinthine colour. A fimilar effedbis produced if either carbonat of foda or micro-cofmic fait be fubftituted inftead of borax.With the latter of thefe fluxes the glafs whilehot is of a deep garnet-red colour.
Siliceous earth - - - 60Vitrified phofphoric acidprepared from bones - 60
Oxyd of nickel - - - 3
produce a honey-yellow glafs, but not quitetranfparent; this defect however is in all pro-bability to be attributed to the phofphat of lime,which phofphoric acid fo prepared almoft alwayscontains.
NIGRIN. See Titanium.
NITRIC. Nitrous Acid . Aqua Forth ofCommerce. Der Salpetersaure. Germ.
This molt important acid is found native ingreat abundance united with potafli, in fomeparts of the Eaft Indies, and it is alfo generatedby the putrefaction of animal matters of variouskinds, as will be explained under the article
* Hatchett. * Kbpr. Atulyt. Eli. I, p, 437.