ALLYL ALCOHOL. 119 



The remaining hydrocarbons of this series Hepty- 

 lene C 7 H 14 , boiling point, 94-96 ; octylene C 8 H 16 , boiling 

 point, 118-120; nonylene C 9 H 18 , boiling point, 140; 

 decatylene C 10 H 20 , boiling point, 158-160 are obtained 

 in the same manner by treating the alcohol chlorides 

 or iodides with alcoholic potassa, or like diamylene 

 C 10 H 20 , boiling point, 150-153 ; dihexylene C 12 H 24 , and 

 triamylene C 15 H 30 , etc., by polymerisation of the simpler 

 hydrocarbons by means of sulphuric acid. 



B. MONATOMIC ALCOHOLS, C n H 2w O. 



The alcohols of this series bear the same relation to 

 the hydrocarbons of the ethylene series, as the alcohols 

 Qnjpn+20 b ear ^ o the hydrocarbons of the marsh gas 

 series. There is at present but one alcohol belonging 

 to this group well known. 



Allyl Alcohol. 

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



Formation and preparation. Four parts glycerin are 

 heated slowly with one part crystallized oxalic acid 

 (an addition of quarter to half per cent, ammonium 

 chloride is advantageous) to 220-230, finally to 260. 

 At first an aqueous solution of formic acid passes over, 

 afterward allyl alcohol. The receiver is changed when 

 the temperature of the mixture has reached 195 ; 

 that which passes over from 195-260 is redistilled, 

 the operation being continued until potassium car- 

 bonate precipitates no oil drops from a specimen of 

 the distillate. The allyl alcohol is then precipitated 

 from the whole distillate with potassium carbonate, 

 purified by treatment with powdered potassium hy- 

 droxide, freed of water, by means of barium hydroxide, 

 and rectified. Or allyl iodide is transformed into allyl 

 oxalate by digestion with silver oxalate ; this is then 

 decomposed by means of dry ammonia gas and the 

 alcohol distilled off. It is also produced by the action 

 of sodium on dichlorhydrine (see Glycerin). 



