On the Hahitudti ef Nitrous Gas. 377 



Ohfervations on the ASllon tvhich the Sulphate of Iron etcerdfes upon Nitrous Gas, and on 

 the Formation of Muriatic Acid. By Citizen Berthollet*. 



M, 



.• HUMBOLDT (in the Bulletin des Sciences, No. 71 & 21) had aflerted that the 

 faculty which fuiphate of iron poflefles of abforbing nitrous gas without the azote which 

 might be mixed with it, was a means of afcertaining with precifion the purity of the nitrous 

 gas employed in eudiometrical experiments. 



Citizen Berthollet, on the contrary, is of opinion, that in this cafe the nitrous gas is 

 not only abforbeJ, but that it is decompofed ; that the oxygen abandons a pari of the 

 azote, and forms, with the other part, nitrous acid ; that this decompofition equally takes 

 place by means of water, mercury, folution of pot-alh, or of hydrogenated fulphuret of 

 alkali; that it is more or lefs complete in proportion as the liquid, in conta£l with this 

 gas, contains bodies which have a greater degree of affinity to nitrous acid, in the formation 

 of which they affift, and nitrites are formed ; that in the' decompofition by water, there is 

 lefs nitrate of ammoniac and more nitrous acid formed than M. Humboldt imagined ; 

 which tends to prove that water did not fumlfli the whole of tlie oxygen of the acid, Cncc 

 the quantity of acid thus formed, is far more confiderable than may be prefumed from the 

 exifting quantity of ammoniac. It is to be remarked that the decompofition becomes more 

 difficult as it is more advanced, and the gas contains lefs oxygen. Citizen Berthollet at- 

 tributes the differences which are obfervable in nitrous gas, to the different proportions in 

 which the oxygen and azote are combined, and he does not think they are owing to azote 

 In a ftate of fimple mixture. 



It is a known fa£l:, that oxigenated muriatic acid, which has no action upon azote, 

 abforbs nitrous gas very well. M. Humboldt obferved in this abforption a refidue, which 

 he attributed to azote mixed with the nitrous gas. Citizen Berthollet having repeated the 

 experiment with nitrous gas, carefully prepared, found a refidue fo fmall as not to 

 'deferve notice. 



In a word, Citizen Berthollet reftores to hydrogenated fulphuret of pot-afh and to 

 phofphorus the property of taking up all the oxygen of the atmofpheric air ; a property 

 which had been contefted by M. Humboldt, who fays, that nitrous gas always indicated 

 the exiftence of a refidue of oxygen in air which had been fubmitted to their a£lion. 

 Citizen Berthollet abfolutely maintains the contrary. Nitrous gas experienced only a flight 

 diminution with the refidue of atmofpheric air decompofed by phofphorus acid ; and he 

 attributes this to the abforption which takes place in the nitrous gas of that portion of 

 phofphorus which had been taken \ip by the azote. 



• Abridged from the Memoirs communicated to the French National Inftitute (In the Bulletin de la 

 Soc. Philora. No. 40.) 



Vol. IV. — ^November i 800. 3C On 



