24 



HYDROCARBONS 



[l D-J. 



Comp. Rend. 132, 1221). Ethylene or methane 

 or both gases are among the products formed 

 by passing the vapour of ethyl alcohol through 

 hot tubes of glass, platinum, or iron, or over 

 heated metals such as zinc, brass, &c., or certain 

 metallic oxides such as those of zinc, tin, &c. 

 (Jahn, Ber. 13, 987 ; Ipatieff, Ber. 34, 3579 ; 

 35, 1047 ; also over heated plumbago crucible 

 material, Ibid. 1058). Ethylene and acetylene 

 are among the products of the pyrogenic de- 

 composition of the vapour of amyl alcohol [22] 

 (Wurtz, Ann. 104, 242). Ethylene is among 

 the products formed by passing n-hexane [23 ; 

 A, &c. J or isobutyl alcohol vapour [18] mixed with 

 air over heated platinum (v. Stepski, Monats. 

 23, 773)- 



[E.] Propyl alcohol [15] gives me- 

 thane among the products formed by 

 passing the vapour over heated mag- 

 nesium (Keiser and Breed, Ch. News, 71, 

 1 1 8), or over heated plumbago crucible 

 material (Ipatieff, Ber. 35, 1059). ^ r 

 n-propyl alcohol gives iodoform by the 

 action of iodine and alkali (Lieben, Ann. 

 Suppl. 7, 3i8; 377), and this can be 

 reduced to methane as above under D. 



Or from n-propyl alcohol through 

 the aldehyde (propanal) by oxidation 

 (Chancel, Ann. 151, 301; Przybytek, 

 Journ. Russ. Soc. 8, 335 ; Lieben and 

 Zeisel, Monats. 4, 14). Propanal gives 

 methane among the products of de- 

 composition of its vapour at a high 

 temperature (Tischtschenko, Ch. Centr. 

 1900, 1, 586; Journ. Russ. Soc. 31, 

 784). 



Or from n-propyl alcohol through 

 n-propyl chloride (see under isopropyl 

 alcohol [16; B]). The latter gives 

 carbon tetrachloride (with the hexa- 

 chloride) when heated with iodine 

 chloride to 200 (Krafft and Merz, Ber. 

 8, 1296). The tetrachloride gives me- 

 thane as below under L. 



Or from isopropyl alcohol [16], being 

 among the products of pyrogenic contact- 

 decomposition (Ipatieff, Ber. 35, 1056). 



[F.] Normal butyl alcohol [17] gives 

 iodoform by the action of iodine and 

 alkali (Lieben ; see above under E). 

 Subsequent treatment as under D. 



Or isobutyl alcohol [18] gives iso- 

 butyl chloride or bromide, and these 

 haloids passed over soda-lime heated 

 to 600 give methane among other 

 products (Nef, Ann. 318, 22, &c.). 

 Methane is among the gases produced 

 by the pyrogenic contact decomposition 



of the vapour of isobutyl alcohol by 

 certain metals (Ipatieff, Ber. 35, 1052 ; 

 also Noyes, Beilstein, I, 115) or by 

 plumbago crucible material (Ipatieff, 

 Ber. 35, 1060). 



[G.] From octyl alcohol [28] through 

 iodoform (Lieben, loc. cit.} and then as 

 above under D. 



[H.] Glycerol [48] gives a small 

 quantity of methane among the products 

 of the dry distillation of the barium 

 compound (Destrem, Ann. Chim. [5] 

 27, 17; 44; Comp. Rend. 90, 1213). 



Or from glycerol through allyl alcohol 

 (see under ethyl alcohol [14 ; G]), which 

 gives methane among the products of 

 pyrogenic contact decomposition bypass- 

 ing the vapour over certain heated metals 

 (Ipatieff, Ber. 35, 1054). Or from 

 glycerol through acrole'in [lOl] as under 

 HH below. 



[I.] From aldehyde [92] through 

 iodoform (Lieben, loc. cit.) and then as 

 above under D. Or aldehyde gives 

 chloral on chlorination (Pinner, Ber. 4, 

 256 ; Wurtz and Vogt, Zeit. [2] 7, 679), 

 and this is decomposed by alkali with 

 the formation of chloroform (Liebig, 

 Ann. 1, 199). The latter, or chloral 

 itself, can be reduced to methane as 

 above under D. 



Aldehyde gives methane among the 

 products of the decomposition of its 

 vapour by heat (Tischtschenko, Ch. 

 Centr. 1900, 1, 586; see also Ipatieff, 

 Ber. 34, 3579) or by pyrogenic contact 

 decomposition by the action of certain 

 metals (Ipatieff, Ber. 35, 1049). Me- 

 thane is among the products of the 

 action of strong aqueous hydriodic acid 

 on aldehyde and many other compounds 

 at a high temperature (Berthelot, Bull. 

 Soc. [2] 7,6o; 9,8; 91; 178; 265; 

 Jahresber. 1867, 342). 



Or aldehyde-ammonia gives methane 

 among the products of its decomposition 

 when heated with a hypochlorite (De 

 Coninck, Comp. Rend. 126, 1042). 



[J.] From acetone [1O6] through 

 chloroform or iodoform (Liebig, Ann. 1, 

 198 ; Lieben, as above under E ; Rother, 

 Jahresber. 1874, 317; Curtman, Beil- 

 stein's'Handbuch,'' I, 189; Suilliotand 

 Raynaud, Bull. Soc. [2] 51, 4 ; Orndorff 

 and Jessel, Am. Ch. Journ. 1O, 365), and 



