N I T

N I T

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at the nitrous oxyd. From ioo grams of zincduring their folution in 300 grains of nitricacid of 1.43 diluted with 14 times its weight ofwater, Mr. Davy obtained 26 cubic inches ofgas, of which were nitrous gas, nitrousoxyd, and the remainder azot.

It is to be obferved that ammonia is knownto be produced in very fenfible quantities duringthe folution of thefe three metals in nitric acid,and the produftion of this alkali feems to beintimately connefted with the evolution ofnitrous oxyd, as has been already explained.

The third method of producing nitrous oxydhas been Hated to be by the diftillation ofnitrat of ammonia. This has been already men-tioned generally under that article, but as thisis the mod economical, and altogether the beltmethod of preparing the gas for chemical pur-pofes and that which is aftually ufed in thelaboratory, the following direftions of a veryable and practical chemift may be ufeful. f“ Introduce into a glafs retort fome pure nitrat“ of ammonia, and apply the heat of an“ Argand’s lamp; the fait will foon liquefy,“ and when it begins to boil gas will be evol-“ ved. Increafe the heat gradually till'the" body and neck of the retort become filled“ with a tranfparent milky white vapour. In“ this Hate the temperature of the fufed nitrat“ is between 340* and 480". After the decom-“ pofition has proceeded for a few minutes, fo“ that the gas evolved quickly enlarges the**' flame of a taper held near the orifice of the“ retort, it may be collected over water, care“ being taken during the whole procefs never“ to fuller the temperature of the fufed nitrat" to rife above 500°, which may eafily be“ judged of from the denfity of the vapours in“ the retort, and from the quiet ebullition of“ the fufed nitrat, for if the heat be increafed“ beyond this point, the vapours acquire a red-“ difh and more tranfparent appearance, and“ the fufed nitrat begins to rife and occupy“ twice the bulk it did before. The nitrous“ oxyd after its generation is allowed to Hand“ over water for at leaH fix hours, and is then« fit for refpiration and other experiments.”

It may be added that as there is always fome.lofs of the gas from abforption by the waterover which it Hands, the. fame, water may beufed repeatedly.

Having thus given the general methods ofprocuring this gas, we proceed to defcribe itschemical properties more particularly.

1 Accum’s Sytlcm. of

Dr. Priefiley found that water readily abforb-ed about half its bulk of this gas, which isagain expelled unaltered. Mr. Davy foundnearly the fame; the utmoH abforption by waterthoroughly purged of air by boiling, and coolingunder mercury being 54 cubic inches of gas to100 of water. Confequently 23300 grs. (theweight of iao cubic inches of water) willabforb 27 grains of the gas. The aqueous folu-tion is fenfibly fweet to the tafie, but fhewsno marks of acidity. The gas is again expelledfrom the water by heat unaltered. When thefaturated water is fliaken with carbonic acidand fulphuretted hydrogen thefe are abforbcd,and the nitrous oxyd expelled unchanged: buton the other hand, the oxyd expels moH of theother gaffes from water and takes their place inthe folution.

Ether and alcohol and the efiential oils abforbthis gas in larger quantity than water, but ap-parently produce no change in its chemicalconflitution.

The concentrated fulphuric and nitric acidsneither abforb nor alter it: tire weaker acids-limply abforb it.

Neither the green muriat nor green fulphatof iron, nor muriat of tin, nor any of the com-mon deoxygenating liquid fubHances appear tohave any effedt on this gas at common tempe-ratures. The fame may be obferved of gafleousbodies, fuch as nitrous gas and fulphurettedhydrogen. Neither is there any alteration pro-duced on nitrous oxyd by the fubHances whichimpart oxygen. Even oxymuriatic gas the moHpowerful oxygenating agent mingles with ni-trous oxyd unaltered.

None of the alkalies either pure or carbonated,,folid or in folution, have any effect on this gaswhen prefented to them ready formed ,. but if the.alkalies are brought in contact with nitrousoxyd in its nafcent fate , a Angular combinationis formed. g The method of making this fpe-cies of neutral fait with potalh, is to mixfulphite of potalh with a little caufiic potalh,(retaining the water of cryfiallization) andinclofe it in an atmofphere of nitrous gas. Thefulphite fi'rH a£¥s on the nitrous gas, convertingit to nitrous oxyd, as already defcribed, (itfelfchanging thereby to fulphat of potalh) and thenitrous oxyd in the moment of formation isabforbed by the free alkali, and forms thisAngular combination. When the procefs isfinilhed the faline mafs confifls of fulphat ofpotalh, probably with fome undecompofed ful-Ihemiftry, t Davy.