ON ISOMERIC NAPTHALENE DERIVATIVES. 179 



Now that the investigation has reached a stage when it is possible 

 to give a complete account of the complex series of processes underlying 

 the formation of the brominated naphthols, it is proposed to submit a 

 considered discussion of the results for publication. 



The Study of Hydro-aromatic Substances. — Rejiort of the Committee, 

 consisting of Dr. E. Divers (Chairraan), Dr. A. W. Crossley 

 (Secretary), Professor W. H. PerkIxV, and Drs. M. 0. Fgrster and 

 Le Sueur. 



Recent Work on Hydro-aromatic Substances. By Dr. A. W. Cro,ssley. 



The following is a summary of the work published on hydro-aromatic 

 compounds since the preparation of the last report.' 



Petroleum. — When acetylene and hydrogen are passed over reduced 

 nickel, there results a mixture of hydrocarbons having the general pro- 

 perties of petroleum. Sabatier and Senderens -' therefore put forwai'd the 

 following suggestion as accounting for the production of natural petro- 

 leum. In the interior of the earth alkali metals and carbides are found 

 and these under the influence of water give hydrogen and acetylene 

 which in contact with finely divided iron, nickel, kc, generate the hydro- 

 carbons of petroleum. This supposition is not considered probable by 

 Aschan,^ who, from experimental results, is led to conclude that the slow 

 distillation of fossil fat in the earth's interior gives rise mainly to an 

 unsaturated hydrocarbon residue, and to a smaller extent to an unsatu- 

 rated complex containing carboxyl. Pressui-e and temperature cause the 

 polymerisation of these residues with production of the naphthenes and 

 naphthene carboxylic acids, which must therefore be regaixled as second- 

 ary products of the distillation of mineral oil in the eartli's interior. 



Mabery ^ has described various hydrocarbons, with from thirteen to 

 twenty-eight carbon atoms, isolated from the portion of Pennsylvanian 

 petroleum, boiling above 216°. 



Synthetical Hydrocarbons. — Starting with optically active substituted 

 hydroxyhexahydrobenzenes, Zelinsky ■' has propared dimethyl- and methyl - 

 ethylhexahydrobenzenes, both of which hydrocarbons show a slight 

 optical activity. 



Harries and Antoni '' have further investigated the method of prepar- 

 ing substituted dihydrobenzenes by distilling the phosphates of certain 

 diamines. The dihydrobenzene prepared from dihydroresorcin by this 

 method adds on four atoms of bromine to give the solid tetrabromide 

 melting at 184° ; whilst starting with dihydroresorcin, and submittinf' it 

 to the method of Crossley and Le Sueur,^ the resulting dihydrobenzene 

 absorbs only two atoms of bromine, forming a dibromide wjiioh melts at 

 104°-5, and decomposes with evolution of hydrogen bromide at 170°.** 



The series of substituted ketotetrahydrobenzenes described by 

 Knoevenagel '^ pro\ides a starting-point for the preparation of substituted 



' Reports, 1902, 120. 2 Compt. liend., 1902, 134, 1185 



= Annalen, 1902, 324, 1. * Amer. CJiem. ,/., 1902, 28, 1G.5 



^ Ber., 1902, 35, 2677. « Annalen, 1903, 328, 8S. 



' J.C.S., 1902, 81, 822. « Crossley and Haas, J.C.S., 1903, 83 49i 



' Annalen, 1894, 281, 225. 



N2 



