404 HISTORICAL INTRODUCTION TO CHEMISTRY CHAP. 



They showed that spirit of wood 1 contained a compound in 

 which they " recognised all the characters of a true alcohol." 

 In order to describe the new alcohol and its derivatives they 

 proposed to give the name METHYLENE (from " /xe'flv, wine, 

 and vA.^7, wood ; that is to say, wine or spirituous liquor of 

 wood") to the radical which it contained (loc. tit. p. 561). 

 They showed that 

 " i. Spirit of wood corresponds with alcohol. 



2. By losing half its water, it forms a gaseous ether. 



3. Its radical unites volume by volume with the 

 hydracids to form neutral anhydrous ethers, etc." (loc.cit. 

 p. 620). 



They regarded the radical methylene, which they were 

 not able to isolate, as a hydrocarbon having the same com- 

 position as ethylene, but containing only half as many atoms ; 

 in just the same way, ethylene in its turn had the same 

 composition as the hydrocarbon (butylene) which Faraday 

 had isolated from oil-gas, but contained only half as many 

 atoms. Using modern formulae' 2 the three compounds are 

 Methylene (not known) CH 2 



Ethylene (defiant gas) C 2 H 4 



Butylene (Faraday's hydrocarbon) C 4 H 8 

 All the ethers derived from spirit of wood could be con- 

 sidered as formed by the addition of water or of acids to 

 methylene, but it was pointed out (loc. at. p. 625) that they 

 might also be regarded as oxides, chlorides, etc., of a 

 hypothetical radical, analogous with ethyl, to which the name 

 METHYL is now given. Thus, again using modern formulae, 2 



1 Discovered by Philip Taylor in 1812, and described by him ten 

 years later in a letter to the editors of the Philosophical Magazine, 1822, 

 60, 315-317- 



2 Dumas formulated the three hydrocarbons as CH, C 2 H 2 , C 4 H 4 . 

 But these were multiplied by four in their compounds ; methylene 

 hydrate (methyl ether, C 2 H 6 O) was C 4 H 4 ,H 2 O or C 4 H 6 O (C = 6); 

 spirit of wood (methyl alcohol, CH 4 O) was methylene bihydrate, 

 C 4 H 4 ,2H 2 O or C 4 H 8 O 2 ; ordinary alcohol (C 2 H 6 O) had now grown to 

 C 8 H ]2 O 2 , Dumas having followed Berzelius and Liebig in regarding 

 it as a hydrate of ether. 



