CARBONIC OXIDE. 397 



with the alkali of the salt and with the water of the oxalic acid, 

 which being thus left at liberty, is decomposed as above. * 



3. PROPERTIES. 



(a.) Smell offensive; colorless; sp. gr. 972, common air being 

 1000. 100 cubic inches weigh 29.65 grains, at medium tempera- 

 ture and pressure ; having the same weight as nitrogen. 



(b.) Does not support combustion; a candle will not burn in it. 

 Inflammable, burning with a blue flame; it takes fire at a low tem- 

 perature, and an iron wire, at dull redness, kindles it ; w^hile the hy- 

 drogen gases require a full ignition or a white heat. 



(c.) It must be washed with lime water, or passed through milk of 

 lime or caustic alkali, as it always comes over with carbonic acid gas. 



(d.) Burn, in a bottle of air, a jet of this gas, issuing from a jar 

 with a stop cock, and it will form carbonic acid.-^ 



(e.) Mixed with common air, it burns more rapidly, but does not 

 explode, except in a few proportions, as 3 of the oxide gas to 1 of air. 



(/.) With oxygen gas 100 volumes and this gas about 200, it ex- 

 plodes by electricity, and the product is 200 of carbonic acid ; the two 

 gases being mixed in the above proportions, when a candle is brought 

 to the mouth of the vessel, burn rapidly, with a whistling noise, but 

 scarcely explode. 



(g.) Fire a jet of it and burn it in a tube, when it will produce 

 feeble musical tones ; and if burnt in a bottle of oxygen gas, over 

 lime water, no water is formed but carbonic acid is produced. 



(h.) It is well to burn and explode some hydrogen, and also varie- 

 ties of carburetted hydrogen, for comparison with this gas, when it 

 will be seen to be very different ; it is less combustible, burns with a 

 different flame and produces carbonic acid only, without water, while 

 the former produces water only, and the latter both water and car- 

 bonic acid. The formation of water in this experiment, is owing 

 to the hydrogen, and that of carbonic acid to the carbon contained 

 in the gas. 



* Edin. Jour, of Sci. No. xii, p. 350. Turner and Dumas. 



t The carburetted hydrogen gases require iron in actual combustion, or 

 the flame of some burning body, in order to set them on fire. 



t When this gas is burned in a bottle of common air, by means of ajar 

 with a stop cock and tube, as in the annexed figure, no water is formed ; 

 but it is otherwise when hydrogen is burned. 



A. Jar of common air. 



B. Jar with a stop cock and tube, containing the gas. 



