ETHYLENE SERIES. 113 



1. Ethylene (Elayl, Olefiant Gas). 

 C 2 H 4 =CII 2 :CH 2 . 



Formation and preparation. By the destructive dis- 

 tillation of the salts of a great many fatty acids ; by 

 distillation of fats, resins, wood, of anthracite coal, 

 and a large number of other organic bodies. Prepared 

 most easily by heating a mixture of 1 part alcohol and 

 4 parts concentrated sulphuric acid, to which has been 

 added sand enough to form a thick pulp, in order to 

 prevent foaming. The gas, which is cooled, is con- 

 ducted through soda ley and sulphuric acid, in order 

 to free it of carbonic and sulphurous anhydrides, alco- 

 hol and ether vapors. 



Properties. Colorless gas ; specific gravity, 0.978 ; 

 not congealing above 110 ; burns with a luminous 

 flame, and is absorbed but little by water. When con- 

 ducted through an ignited tube, it is decomposed into 

 carbon, marsh gas, hydrogen, and acetylene. It com- 

 bines with sulphuric anhydride to form carbyl sul- 

 phate; English sulphuric acid absorbs it very slowly, 

 forming ethylsulphuric acid. Hydrochloric, hydro- 

 bromic, and hydriodic acids combine slowly with it, 

 forming ethyl chloride, bromide, and iodide. A solu- 

 tion of platinum chloride in hydrochloric acid absorbs 

 it slowly and, on the addition of potassium chloride, 

 lemon-colored crystals of C 2 H 4 .PtCl 2 .KCl + H 2 are 

 deposited. 



Ethylene chloride (Elayl chloride), C 2 H 4 C1 2 = 

 CII 2 C1.CII 2 C1, is formed from ethylene and chlorine by 

 direct combination. In order to prepare it, ethylene 

 gas is conducted into a gently heated chlorine mixture 

 and the chloride finally distilled off. Colorless liquid, 

 of an ethereal odor ; of specific gravity 1.271 at ; 

 boiling point, 85. When boiled with alcoholic po- 

 tassa, it is converted into chlorethylene, C 2 IPC1, water 

 and potassium chloride being formed at the same time. 

 A gas condensable at 18. Chlorine acts upon 

 ethylene chloride, yielding substitution-products, and, 

 according to the length of time occupied in the Action, 



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