ETHYLENE SERIES. 115 



temperature. Can be most easily prepared by conduct 

 ing the gas into an alcoholic solution of iodine, to 

 which is added an excess of iodine. Colorless crys 

 tals, fusing at 73, which, when kept in a dark place, 

 slowly turn yellow. Exposed to the light, this dis 

 coloration takes place rapidly. Sublimable; above 

 80, however, it is resolved into iodine and ethylene. 



Ethylene nitrite, C 2 II 4 (^ T 2 ) 2 . Is produced by 

 direct combination of ethylene with hyponitric acid. 

 Four-sided prisms, which fuse at 37.5. 



Chlornitrocarbon, C 2 C1 4 (N0 2 ) 2 . By heating carbon 

 chloride C 2 C1 4 with hyponitric acid in sealed tubes to 

 110-120. Colorless, crystalline mass. At 140 it is 

 resolved into C 2 C1 4 and hyponitric acid. 



Ethylene cyanide, C 4 H 4 ^ 2 = C 2 H 4 (CT) 2 . Is ob 

 tained by heating ethylene chloride, or better, bromide, 

 in an alcoholic solution with potassium cyanide. 

 Crystalline mass, fusing at about 37. * Not volatile, 

 without undergoing decomposition. Heated with an 

 alcoholic solution of potassa, it yields ammonia and 

 potassium succinate ; it combines with nascent hydro 

 gen, forming butylene diamine C 4 H 8 (NH 2 ) 2 . 



2. Propylenc. 

 C 3 H 6 CH 3 .CH:CH 2 . 



Is produced together with the homologous hydrocar 

 bons from a large number of organic bodies, when 

 these are distilled either alone or mixed with lime. It 

 can be obtained pure by heating glycerin with phos 

 phorus iodide, or by heating the allyl iodide C 3 H 5 I, 

 which is formed simultaneously with it, with mercury 

 or zinc and fuming hydrochloric acid ; or, most readily, 

 by heating isopropyl iodide with an alcoholic solution 

 of potassa on a water-bath. It is also produced together 

 with ethyl bromide by the action of zincethyl on 

 bromoform. Colorless gas, with an odor similar to 

 that of ethylene ; condensable by pressure, but is still 



