Structure of Simpler Organic Compounds. 67 



which the members may be regarded as substances derived 

 from inorganic compounds by the replacement of a 

 hydrogen by an " alkyl " radicle (see p. 64). Thus, by 

 the replacement * of the hydrogen atoms of water by 

 methyl, the compounds 



H 5 CH 3X 



/ / 



methyl alcohol and methyl ether, may be derived. 

 In the same way, from the acids 



HC1 H 2 S0 4 H S P0 4 



substances with the formulae 



CH 3 C1 CH 3 HS0 4 /nTT . pn 



/PITT \ Q/"l \^'-'--^3/3-*- ^4 61/C.j 



(\jrL 3 )^\j 4 



can be derived, and are actually known. 



It is not, therefore, unreasonable to regard methyl 



alcohol as an analogue of water, and to assign to it the 



formula CH 3 (OH) (or CH 3 OH), and to assume that it 



contains two groups, namely, a methyl group of a carbon 



atom united to three hydrogen atoms, which group can 



remain intact through whole series of operations, and a 



hydroxyl group, the main characteristics of which are 



that it is replaceable by a halogen, and that the hydrogen 



as replaceable by an alkali metal, which acts upon the 



alcohol with evolution of hydrogen. The oxygen of the 



E hydroxyl group must in this case be assumed to be directly 



1 united to a carbon atom and one hydrogen atom, which 



51 latter differs in its reactions from the other three hydrogen 



r atoms, which are directly combined with the carbon. 



a A large series of homologues of methyl and ethyl alcohol 



c are known, some of which, like ethyl alcohol, are products 



* "Replacement " here does not mean that the reaction can be accomplished 

 by a direct experimental method. The term is applied only to the graphical 

 formulae, the main object of which is to indicate the relative arrangement of 

 the atoms to one another. 



