ALCOHOLS. 269 



by treating them with the alkaline hydrates, when the acid 

 enters into combination with the alkali, whilst the alcohols are 

 liberated according to the general formula : 



A,!?) + KH - Aol> + A1RHO - 



Alcohols may be obtained artificially by various processes, as, 

 for instance, by treating hydrocarbons with chlorine, when the 

 chloride of a hydrocarbon residue is formed, which may be de- 

 composed by alkaline hydrates in order to replace the chlorine 

 by hydroxyl, when an alcohol is formed. For instance : 



C 2 H 6 + 201 = C 2 H 5 C1 + HC1. 



Ethane. Ethyl 



chloride. 



C 2 H 5 C1 + KHO = KC1 + C 2 H 5 HO. 



Ethyl Potassium Potassium Ethyl 



chloride. hydrate. chloride. alcohol. 



Properties of alcohols. Alcohols are generally colorless, neutral 

 liquids ; some of the higher members are solids, none is gaseous 

 at the ordinary temperature. Most alcohols are specifically 

 lighter than water ; the lower members are soluble in or mix 

 with water in all proportions; the higher members are less 

 soluble, and, finally, insoluble. Most alcohols are volatile 

 without decomposition ; some of the highest members, however, 

 decompose before being volatilized. 



Although alcohols are neutral substances, it is possible to 

 replace the hydrogen of the hydroxyl by metals, as, for instance, 

 CH 3 HO = methyl alcohol ; CH 3 NaO = sodium methyl oxide 

 or sodium methylate. 



The oxygen of alcohols may be replaced by sulphur, when 

 compounds are formed known as mercaptans; these bodies 

 may be obtained by treating the chlorides of hydrocarbon 

 residues with potassium sulphydrate : 



C 2 H 5 C1 + KHS = KC1 + C 2 H 5 H8. 



By replacement of the hydrogen of the hydroxyl in alcohols 

 by alcohol radicals ethers are formed ; by replacing the same 

 hydrogen with acid radicals compound ethers are produced. 



Most alcohols are known in two, or even three, metameric 

 forms, which are distinguished as normal or primary, secondary, 

 and tertiary alcohols. 



