xvii MOLECULAR ARCHITECTURE 423 



HI 



H VN 

 PhJ 



the substances tabulated by Hofmann are 



1. Amide-bases (primary amines) 



H 

 Aniline or phenylamine H [ N Ethylamine 



Et 



2. Imide-bases (secondary amines) 



H ) H \ H 



Et [N Ethylphenylanrine Ay VN Amyl- Et VN Diethylamine 



PhJ PhJ phenylamine Et 

 (ethylaniline) (amylaniline) 



3. Nitrile-bases (tertiary amines) 



Et ) Et ) Et 



Et [ N Diethylphenylamine Ay VN Ethylamyl- Et \ N Triethylamine 



Ph) PhJ phenylamine Et 

 (diethylaniline) (ethylamylaniline) 



The classification into PRIMARY, SECONDARY, and TERTIARY 

 AMINES was introduced in 1856 by Gerhard t, who suggested 

 that 



" One might call the nitrogen-compounds primary ', second- 

 ary, and tertiary, according as they represent the ammonia- 

 type with substitution of one, of two, or of three atoms of 

 hydrogen" (Treatise, 1856, IV. 592). 



Williamson (1852) on etherification, As recently as 

 1852 it was still uncertain whether or not alcohol "contains 

 ether and water," i.e. whether the formation of ether from 

 alcohol should be represented by the equation 



C 4 H 10 0,H 2 = C 4 H 10 + H 2 0, 



or, as Dumas had represented it twenty-four years before, by 

 the equation 



Williamson ("Theory of Etherification, " Journ. Chem. Soc.> 

 1852, 4, 106-112, 229-239) tested this point by acting on 

 alcohol with potassium, forming potassium ethoxide and 

 hydrogen, 



C 2 H 6 O + K - C 2 H 5 OK + JH 2 



Potassium ethoxide. 



