vin THE BURNING OF INFLAMMABLE GASES 155 



45, 178-191). They proved that it was a HYDROCARBON, 

 i.e., a compound of carbon and hydrogen only. They 

 distinguished it as " oily carburetted hydrogen," now 

 OLEFIANT GAS, from the property which it possessed of 

 combining with chlorine gas (Chapter XI) to form an oil 

 known as DUTCH LIQUID. The gas is now called ETHYLENE, 

 and the liquid ETHYLENE CHLORIDE. 



The gas was also investigated by Dalton, who describes 

 it as follows : 



"Olefiant gas may be produced by mixing 2 measures 

 of sulphuric acid with i measure of alcohol ; this mixture 

 in a gas bottle must be heated to about 300 [Fahrenheit] by 

 a lamp, when the liquid exhibits the appearance of ebullition, 

 and the gas comes over : it should be passed through water, 

 to absorb any sulphurous acid which may be generated." 



" This gas is unfit for respiration, and extinguishes flame, 

 but it is highly combustible. . . . Olefiant gas burns with a 

 dense, white flame. It explodes with uncommon violence 

 when mixed with oxygen and electrified. . . . : unless a great 

 excess of oxygen be used, the charcoal is partly thrown down, 

 and it makes the gas turbid after explosion ; the result 

 in this case affords less carbonic acid than is due " (New 

 System, 1810, II. 438 and 440). 



Composition of olefiant gas. Dalton investigated the 

 volumetric relationships of the gas. He showed that it 

 combined with its own volume of chlorine (loc. cit., p. 439). 

 When exploded with an excess of oxygen, some carbon 

 remained unburnt, but a large contraction occurred, the 

 proportional volumes being (loc. tit., p. 440) : 



olefiant gas + oxygen -> carbonic anhydride + water ; 



100 vols. 270 to 300 vols 185 or 190 vols. 

 or roughly 



i vol. <3 vols. <2 vols. 



When mixed with only its own volume of oxygen and 

 exploded, an expansion was produced instead of a contrac- 



