( 293 ) 
Action of sulphur on m.-aylene. Sulphur boiled with m-xylene not 
only gave a much smaller evolution of hydrogen sulphide than in the 
case of p-xylene but the amount was even less than that obtained on 
boiling sulphur with toluene. m-Xylene which had been boiled for ¢ 
considerable time with sulphur was quite as free from mercaptane 
as the similarly treated toluene and p-xylene. 
We now proceeded to heat sulphur and m-xylene in sealed tubes 
at 200°. After the heating had lasted for 70 hours, the sulphur had 
totally disappeared and the tubes could be opened. Streams of hydrogen 
sulphide escaped. From the liquid obtained the xylene was distilled 
off and the liquid non-crystallisable residue was freed from sulphur 
by boiling with solution of sodium sulphide. As it was not impro- 
bable that both m.m. dimethylbenzyl and dimethylstilbene might have 
been formed (to judge from the behaviour of p-xylene) and as the 
first named substance is, according to Vorrraru ') and Moritz and 
WOLrPrENSTEIN *), a liquid and the unknown m.m. dimethylstilbene 
probably a erystallisable substance it was tried (although in vain) to 
effect a separation of these two substances by heating in a current 
of steam, by fractional distillation at ordinary pressure and also by 
solvents. The suspected presence of a stilbene in that liquid was, 
however, soon proved when bromine was added to its ethereal solu- 
tion and the whole placed in a freezing mixture. A bromine-addition 
product now crystallised in abundance. The addition of bromine was 
continued until a small excess was present. The crystallised 
product after being recrystallised twice from xylene had a constant 
melting point of 167—168°. A bromine determination according to 
Carrus gave 44.02 °/, of bromine, the calculated quantity for dimethyl- 
stilbene dibromide being 43.50 °/,. 
The dibromide was used to prepare the hydrocarbon itself. For this 
purpose it was dissolved in xylene and boiled with molecular silver 
or sodium wire for 6 hours in a reflex apparatus. From the xylene 
solution obtained the xylene was removed by distillation ; the residual 
liquid crystallised on cooling and the crystalline mass could be readily 
purified by reerystallisation from alcohol. The substance is very diffi- 
cult to burn; the combustion only succeeded by intimately mixing 
it with lead chromate and potassium bichromate. The elementary 
analysis gave the following result : 
69410 Ae HE A OLEN 
©. 92.80. 17E 70 
Oneca en ete ate rd ze 
Calculated for C,, H,, . 
1) Zeitschr. f. Chemie 1866. P. 489. 
2) Ber. D. Chem. Ges. Band 32. P. 2532, 
