68 PRACTICAL ORGANIC AND BIO-CHEMISTRY 



PROPYL ALCOHOLS. C 3 H 7 OH. 



Normal Propyl Alcohol. CH 3 . CH 2 . CH 2 OH. 



Normal propyl alcohol is formed in the process of alcoholic fermen- 

 tation and is contained in fusel oil, from which it is obtained by frac- 

 tional distillation. It is present to the extent of about 3 per cent, in 

 the fusel oil obtained from potato spirit. 



It is a liquid resembling ethyl alcohol but with a less pleasant 

 smell, and burns with a luminous flame. It boils at 97 and has a sp. 

 gr. of -807 at 15. 



3 



Isopropyl Alcohol. \CHOH. 



CH/ 



Isopropyl alcohol is prepared either by the reduction of acetone 

 with sodium amalgam or from isopropyl iodide by boiling it with lead 

 hydroxide and water. Isopropyl iodide is prepared by the action of 

 phosphorus and iodine upon dilute glycerol. 



It is a liquid resembling normal propyl alcohol, but it boils at 82" 

 and has a sp. gr. of 792 at 15. 



CH 2 



BUTYL ALCOHOLS. C 4 H OH. 



Four isomers are possible in the case of the butyl alcohols : 

 CH 2 OH CH 2 OH CH 3 CH 3 



CH CHOH COH 



CH 3 CH 3 CH 2 CH 3 CH 3 



Normal Primary Normal Tertiary 



primary isobutyl secondary butyl 



butyl alcohol. butyl alcohol, 



alcohol. alcohol. 



The chief of these is primary isobutyl alcohol which is formed in 

 alcoholic fermentation and is separated by fractional distillation from 

 the fusel oil. 



Normal primary butyl alcohol has once been found in fusel oil. 

 It is formed by the action of the Schizomycetes upon glyceroL 

 Bacillus butylicus (contained in the excrement of cows) produces 6-& 

 per cent, from glycerol and 10 per cent, from mannitol. Normal 

 secondary butyl alcohol and tertiary butyl alcohol are prepared by 

 synthetical methods. The butyl alcohols are liquids with the following 

 boiling-points and specific gravities at 20 : 



B.P. Sp. Gr. B.P. Sp. Gr. 



Normal primary 117 '810 Primary isobutyl 107 -806 



Normal secondary 100 '8c8 Tertiary 83 786 



They are not miscible with water in all proportions ; normal 

 primary butyl alcohol requires 12 parts of water to dissolve it. 



