ETHYLENE SERIES. 117 



between 4 and +8. Combines with hydriodic acid, 

 forming secondary butyl iodide (p. 69). 



The 'bromide, CH 3 .CH 2 .CHBr.CH 2 Br, boils at 156- 

 159. 



2. Isobutylene, ^ } C:CH 2 . Is produced by the 



action of alcoholic potassa on the iodides of isobutyl 

 alcohol and tertiary butyl alcohol; by the decomposi- 

 tion of amyl alcohol at red heat; and by the electrol- 

 ysis of potassium valerate. Boiling point 6. Unites 

 with hydriodic acid, forming tertiary butyl iodide. 

 Is absorbed by sulphuric acid, a sulpho-acid being 

 formed, which yields tertiary butyl alcohol (p. 69), 

 when subjected to distillation with water. 



PTT3 1 



The bromide, ^ 3 [ CBr.CH 2 Br, boils at 160. 



3. Pseudobutylene, CH 3 .CH:CH.CH 3 . Is obtained 

 by the action of alcoholic potassa, silver oxide and 

 water, or silver acetate on secondary butyl iodide ; and 

 by heating secondary butyl alcohol to 250. Boiling 

 point, + 3 ; congeals as a crystalline mass when cooled 

 down to a very low temperature. Combines with 

 hydriodic acid, regenerating; secondary butyl iodide. 



The bromide, CH 3 CHBr.CHBr.CH 3 , boils at 159. 



A fourth butylene, the constitution of which is not 

 well known, results from the action of zincethyl on 

 monobrometlvylene. It boils at 5 ; yields a bromide 

 that boils at 166; and, as it seems, combines with 

 hydriodic acid, forming isobutyl iodide. 



4. Amylenes. 

 C 5 H 10 . 



1. Ethylallyl, C 5 H 10 = CH 3 .CH 2 .CH 2 .CH:CH 2 . Is 



obtained by the action of zincethyl on allyl iodide. 

 Colorless liquid, boiling at 37. Combines with hydri- 

 odic acid, forming isoamyl iodide (p. 71); with bro- 

 mine yielding a bromide, C 5 H 10 Bi^, that boils at about 

 175. 



