DEUTOXIDE OF NITROGEN. 455 



by meeting with the oxygen in the air, in the cavities, and excites 

 the glottis to violent spasmodic action with most distressing irritation.* 



(d.) Action on combustibles. This is very various; some com- 

 bustibles that burn in common air, do not burn in this gas, as a 

 candle, sulphur, and most common combustibles, which, although on 

 fire, are extinguished by immersion in nitric oxide. 



Phosphorus, if previously kindled, burns with great energy, but it 

 may be melted in this gas without inflaming. Homberg's pyro- 

 phous is spontaneously inflamed. 



Charcoal, previously ignited, takes fire, but burns feebly.-^ Hydro- 

 gen gas, mingled with the nitric oxide, does not explode by a lighted 

 candle, but burns quietly, with a greenish white flame, of peculiar and 

 agreeable hue, which is modified between that of the yellow vapors 

 of nitrous acid, and the pale bluish flame of the hydrogen. 



Carburetted hydrogen no explosion, except between 7 measures 

 of nitric oxide gas, and 1 of the olefiant. 



Spongy platinum acts upon a mixture of hydrogen gas with nitric 

 oxide, in proper proportions ; acid and nitrogen and watery vapor are 

 evolved. 



Ammonia 100 parts, and this gas 150, detonate by the electric 

 spark, and by a spontaneous action, nitrogen is liberated in the 

 course of a month. J 



(e.) Action on oxygen ga&. This is the most interesting of all 

 the relations of nitric oxide gas. Wherever it meets with oxygen 

 gas, either alone, or in mixture with other gases, it produces deep 

 brownish red fumes of nitrous acid. 



This property need be indicated here, only in a general way, be- 

 because it will be more fully stated under the nitrous acid. 



1 . Fill a tall glass tube with infusion of litmus, or purple cabbage'; 

 pass up some bubbles of nitric oxide gas, that have stood for an hour 

 or two over water ; there will be no alteration in the color of the 

 litmus ; now add some oxygen gas, or common air ; there will still 

 be no change till the bubbles reach the nitric oxide ; then red fumes 

 will be produced, which will promptly change the color of the liquid 

 to red, and the water will rise rapidly, on account of the absorption 

 of the acid vapor. 



2. The above experiment may be repeated, only using a tall air 

 jar, and common air. The observer who sees the result for the first 



* As I once experienced, having breathed some of it, for nitrous oxide, from an 

 air vessel. Insects that will live in some of the other noxious gases die in this, and 

 fishes die in water impregnated with it. Murray. 



t Murray. Most authors say brilliantly, but in numerous trials, I could never 

 make it burn at all. It will never answer for a class experiment. May it not be 

 that nitric oxide gas has been in this case confounded with nitrous acid vapor, which 

 is more energetic in supporting combustion ? t Henry. 



