N I T

NIT

( no )

The fame difference as exifts between the redand green fulphat of iron is found in the redand pale muriat of iron and fimilar habitudeswith nitrous gas; for the red muriat has verylittle action on this gas, but the pale muriatabforbs it with ftill more eagernefs than thepale fulphat. This muriat is formed by dif-folving iron filings in muriatic acid, taking careto keep a quantity of undiffolved metal in thefolution, and preferving it in a clofely corkedbottle. This folution is of a pale green colour,and .gives a white precipitate with pruffiat ofpotafh. One cubic inch of the folution highlyconcentrated will abforb nearly 24 inches ofpure nitrous gas, which changes the colour to avery dark brown but produces no precipitate.The folution of the green muriat or fulphatbefore it is employed to abforb nitrous gas foreudiometrical purpofes, fhould be boiled for afew minutes to expel the fulphuretted hydrogenwhich it may contain.

The other fails known relating to its de-compofition will be mentioned in the followingarticle of nitrous oxyd, which as it contains lefs ox-ygen than nitrous gas, is produced by the ailionof deoxygenating fubftances on nitrous gas.

NITROUS GAS Etherized is a peculiarinflammable gas formed by the mutual a£tionof nitric acid and alcohol. See Ether nitrous.

NITROUS OXYD, or Gajfeous oxyd of azot.Dephlogificated nitrous air of Dr. Prieftley.

This gas was firft difcovered by Dr. Prieftleyby expofmg iron to nitrous gas; he has alfo given-a number of curious experiments on the mode ofits formation and has detailed a great numberof its phyfical and chemical properties. Fromthe circumftance of its fupporting combuftionin an eminent degree (in many inftances almoftequal to oxygen gas in this refpedt ) and beingproduced by the decompofition of nitrous gas,Dr. Prieftley gave it the name of dephlogificatednitrous air , but as this term is founded on thedoubtful theory of phlogifton, and as it mightlead to the miftake of fuppofing that this gasreally contained more oxygen than nitrous gas,Mr. Davy’s appellation of nitrous oxyd is muchto be preferred.

Since the experiments of Dr. Prieftley thisfubftance has been the fubjedt of very carefulrefenrch by the Dutch chemifts, and otherphilofophers, and in particular by Mr. Davywhofe excellent memoir on nitrous oxyd hasalmoft fupplied every thing that the great dif-coverer had left to his fucceflbrs.

Nitrous oxyd is a fubftance compofed, likenitrous gas, of azot and oxygen, but in which

the oxygen is in a fmaller proportion, fo thatin this refpect it holds an intermediate placebetween nitrous gas and atmofpheric air, whichlaft is the leaft oxygenated of all the Amplenatural combinations of thefe two elements.However, though nitrous oxyd contains lefsoxygen than nitrous gas, the mode of combina-tion appears to differ confiderably and much toinfluence its power of containing combuftionand other chemical properties.

The diftinguiftiing properties of nitrous oxydare the following: it is readily abforbed bywater to about half the bulk of this fluid, andthe folution has a fweetifh tafte, but it is not inthe leaft degree acid: a candle burns in it withan enlarged flame and crackling noife: phof-phorus actually ignited burns in it with nearlyas much brilliance as in oxygen gas: fulphurwhen burning in the common way with afeeble blue flame is immediately extinguifhed inthe gas, but when burning vehemently beforeintroduction, the combuftion continues withincreafed rapidity: ignited charcoal burns in itnearly as in oxygen gas: neither oxygen nornitrous gas have any fenlible effect on it at acommon temperature: animals inclofed in thegas foon die, but it may be breathed whenmixed with common air. Other properties ofthis gas will prefently be mentioned, but theaction of water, of combuftible bodies, and theinaftion of oxygen and nitrous gas, will fuffi-ciently diftinguilh it.

Therefore in the decompofitions of nitrousgas the quantity of nitrous oxyd produced maybe found by agitating the relidual gas in water.But if any unaltered nitrous gas remain (whichis very commonly the cafe, and is fhewn by thediminution and red fumes with oxygen gas) itmuft be previoufly abforbed by fulphat or muriat.of iron, which has no efleet on nitrous oxyd,after which the nitrous oxyd may be abforbedby water, and the remaining gas is pure azot.

Nitrous oxyd has never been found native norhas it been detailed in any of the procefles ofnature. It is produced artificially in feveralways, namely:

rft. From the decompofition of nitrous gasby thofe fubftances which abforb its oxygen.

2diy. From the adtion of nitric acid on manyof the metals under particular circumftances.

3dly. From the decompofition of nitrat ofammonia by Ample diftillation.

Each of thefe methods fhall be diftindtly

noticed.

The fubftances that abforb oxygen fromnitrous gas are many of them thofe that abforb