68 Biological Chemistry. 



of fermentation produced by micro-organisms. In the 

 members of the series higher than ethyl alcohol isomerides 

 exist. Thus two alcohols with three carbon atoms, 

 namely 



CH, 



rTT rnr 



CH 2 and \/ 



CH. 

 CH 2 -OH 



3 ' 



./ 



OH 



are known, the former being known as propyl, and the 

 latter as isopropyl alcohol. The former contains the 

 propyl and the latter the ^sopropyl radicle. There are 

 four butyl alcohols, or alcohols with four carbon atoms. 

 These have the formulae 



CH 3 



CH 3 CH 3 CH 3 CH 3 CH 2 CH 3 CH 3 CH 3 



t 



\/ \ / and 



CJ 



CH 2 CH CHOH C OH 



H 2 CH 2 OH 



CH 2 OH 



(1) (2) (3) (4) 



The first of these is normal butyl alcohol, the second iso- 

 butyl alcohol, the third secondary butyl alcohol, and the 

 fourth tertiary butyl alcohol. The term " primary 

 alcohol " is applied to those alcohols in which the hydroxyl 

 group is attached to a carbon atom to which two other 

 hydrogen atoms are also attached ( CH 2 OH). Both (1) 

 and (2) would, therefore, be called primary alcohols. Where 

 the hydroxyl group is united to a carbon atom attached to 

 only one hydrogen atom (and to two alkyl radicles, that 

 is, through carbon atoms), the alcohol is said to be " second- 

 ary " (^>CHOH, as in No. 3) ; and where it is united to a 

 carbon atom which is attached to no hydrogen atom but' 



