116 ETHYLENE SEEIES. 



gaseous at 40. It is but slightly absorbed by 

 water, more easily by alcohol (12 volumes). It eon- 

 ducts itself like ethylene, and combines, like this gas, 

 directly with chlorine, bromine, and iodine. It com- 

 bines with hydriodic acid, forming isopropyl iodide. 

 By agitating it with concentrated sulphuric acid, a 

 sulpho-acid is formed, which, when distilled with water, 

 yields isopropy] alcohol. 



Propylene chloride, C 3 H 6 C1 2 = CH 3 .CHC1.CH 2 C1 

 (isomeric with methylchloracetol, p. 110), is also pro- 

 duced by the action of chlorine on propyl hydride. 

 Colorless liquid, boiling at 93-98. 



Monochlorpropylene, C 3 H 5 C1 = CH 3 .CC1:CH 2 . Is 



produced from propylene chloride, and also from the 

 isomeric methylchloracetol by the action of alcoholic 

 potassa. Liquid, boiling at 23. 



Propylene bromide, CWBr 2 . Is also obtained 

 by allowing bromine to act upon isopropyl bromide ; 

 and, together with the following compound, by the 

 action of hydrobromic acid on allyl alcohol. Colorless 

 liquid, boiling at 142. 



Trimethylene bromide, C 3 H 6 Br 2 = CKPBr.CH 2 . 

 CH 2 Br. A liquid, boiling at 160-163; specific gravity, 

 2.0177 at 0. 



Monobrompropylene, C 3 H 5 Br. Liquid; boils at 

 56.5. 



3. Butylenes. 

 C 4 H 8 . 



There are three butylenes of different constitution 

 known. 



1. Butvlene (Methylallyl), CH 3 .CH 2 .CH:CH 2 . Is 



obtained by decomposing a mixture of allyl iodide and 

 methyl iodide with sodium. Colorless liquid, boiling 



