402 OLEFIANT GAS. 



(h.) Carbonic acid and other gases, also diminish its inflamma- 

 bility. 



(i.) Its complete combustion requires more than two volumes of ox- 

 ygen two are consumed, and carbonic acid, equal in volume, to the 

 inflammable gas, is produced and water is formed. 



(/.) There being in carbonic acid exactly its volume of oxygen, 

 it follows that half the gas used went to form water along with the hy- 

 drogen, of which there were therefore 2 volumes, and this, along with 

 1 of gaseous carbon, existed in the compass of 1 volume. 



(k.) It hence* results that the light carburetted hydrogen gas is 

 composed for 100 cub. inches, at med. temp, and pressure, of 

 charcoal, 12.69 grains, 74.87 grains, 

 hydrogen, 4.26 " 25.13 " 



16.95f 100.00 



(/.) On respiration and animal life, its effects are eminently noxious, 

 and speedily fatal. 



(m.) Not decomposed by electricity, nor by heat in ignited tubes, 

 unless very intense, as stated above. 



4. CONSTITUTION. Two volumes of hydrogen and one volume 

 of gaseous carbon, condensed into one volume ; 1 equivalent of char- 

 coal, = 6-}-2 of hydrogen, =8 for the equivalent of the compound. 



OLEFIANT GAS.J 



1. HISTORY. Discovered at Haarlem, in Holland, in 1796, by 

 the associated Dutch chemists ; but Mr. Dalton, of Manchester, 

 gave the first accurate account of its composition. 



2. NAME. With chlorine, in equal volumes, it is condensed into 

 a substance resembling an oil ; hence the name, from oleum Jio ; the 

 compound substance produced, being however, not an oil, the name 

 was unappropriate, but it is still generally retained. 



3. PREPARATION.^ 



(a.) Alcohol 1 measure, sulphuric acid 2 or 3 ; mix them cau- 

 tiously, in a retort, of which they must not occupy more than J of 

 the body. Gentle heat is gradually applied the mixture soon be- 



* 16.93. Dr. Turner. 16.94, on p. 401, (e.) of this work. 



t For carbonic acid, with 1 vol. carbon and 1 of oxygen, weighs 46.597 grains for 

 the 100 cub inches, deduct the weight of the oxygen, 33.888, leaves 12.70 nearly, 

 for the weight of the carbon in vapor, and the weight of hydrogen being, for 100 cu- 

 bic inches, 2.118 ; twice that sum is 4.236, and this*+12. 70 =16.936. These numbers 

 are taken from Brande's Tables, and vary slightly from those quoted elsewhere in 

 the pages of this work. 



I Or heavy carburetted hydrogen gas, bi-carburetted, and per-carburetted hydro- 

 gen, and hydroguret of carbon. The first name, that of olefiant gas, is generally 

 employed. 



By passing the vapor of alcohol over ignited siliceous, or argillaceous earth, 

 nearly pure olefiant gas is obtained. 



