Chemistry and Physics. 267 
a the others are analogues of risa and the last 
derivatives of ene ” Bees is derived from “toluol in the same manner 
asphenyl from benzol ; 20, ys 1a+H,. Anthracen is derived 
from toluol by a similar condensation ‘and subtraction of hydrogen 
a—C.,H,,+3H,. As, according to Berthelot’s view, toluol 
may ‘be derived from benzol by the substitution of marsh-gas for hydrogen, 
nzol =C toluol =C Anthracen may be con- 
sidered as formed De ihe union By sagt residue C,,H, with the 
h-gas residue C,H and has therefore the rational formula [C,,H, 
(C_H)]., that is, C,,H,[C,,H,(C,H,)]. This explains why a marsh- 
is necessary for the formation of anthracen and why this 
hydrocarbon is not formed i composition of pure benzol. The 
i¢ compound with picric “n oer phenyl ‘does no 
cei in considerable quantity m uid hydroe 
formation of styrolene may be ihatisind by the equation 
C,2H,.+C,H,=C,.H.+H:2.- 
Naphialin 3 is enn by the reaction C,2 H,+2C,H,=C,,H a 
i 12 
second of H, in .H f *by 
the reaction 2C,,H,+C, H, uit, oH, 40H 
4 © lands to'the rations) formals C,,H,IC, oH, (C. ne ee 
Pure sito is Blew’ decom at a red heat with formation of 
benzol and ace ty] etCs 
Again benzol ay pore lene heated “fogether produce a certain quantity 
of styrolene, though this hydrocarbon is not the chief product. When 
styrolene and hydrogen, C,¢HetHa, are e | 
‘ube, benzol and ethylene are form 
ole: 
4 and ethylene and ag Cc 3a +C,H,, ye benzol 
and naphtalene both in considerable quantity. The benzol results [ 
nod decomposition of the styrolene itself but the naphtalin is formed 
the direct action of ethylene upon styrolene : i ait 
C,H alC, H,(H,)]+C,H2(H3) )=C, 3H, [C,H2(C,H2)+ = 
