1185 
there remains a colourless, transparent, gelatinous product which 
swells in contact with benzene, but does not dissolve therein. 
The liquid boiling at about 100° in vaeuo, when distilled at the 
ordinary pressure passes over at + 215° with formation, however, 
of products with a higher boiling point. After fractional distillation 
in vaeuo the bulk was obtained as a perfectly colourless liquid which 
is more viscous than hexatriene (b.p. 99°.5 at 16 mm. pressure). 
The elementary analysis (found: C 89.43, H 10.1 ; calculated C 89.91, 
H 10.09) and the vapour density determination (according to HOFMANN: 
found 5.5; calculated 5.5) led to the formula C,, H,,, so that the sub- 
stance is to be considered as a dimer of hexatriene. 
Dr =1);880 ne = 1551951 
MR = 55.2 Calculated for C,, H,, |g 53.54 5) 
The density “is considerably higher than that of hexatriene (0.7498 
at 13°) whereas the exaltation of the molecular refraction is much 
smaller. This is particularly striking when we compare the spec. 
exaltations. 
For hexatriene E > = 3.125 
For the dimer E =, = 1.037 
The dimer of hexatriene readily forms an additive compound with 
one mol. of bromine; on further addition much hydrogen bromide 
is eliminated. It is rapidly oxidised by a solution of potassium 
permanganate. The investigation thereof is being continued. 
The method by which hexatriene was formerly obtained (inter- 
action of formic acid on s. divinylglycol) did not exclude the possi- 
bility that it might be contaminated with hydrogenated derivatives 
thereof and hence it was thought desirable to try other means and 
get it in a pure condition by regeneration from crystalline deri- 
vatives. Mr. Murnier who for a considerable time has been engaged 
on the study of hexatriene has succeeded in regenerating the hy- 
drocarbon from the beautifully crystallised dibromo additive com: 
pound. By treating hexatriene witb sulphur dioxide he has also 
obtained a solid product, the investigation of which is not yet con- 
cluded and from which the hydrocarbon may be prepared also. 
It was further to be expected that hexatriene would also be for 
med by dehydration of the hexadiene 1.5-ol 4, which alcohol might 
be obtained by reduction of the divinylethylene oxide recently descri- 
') Here it has been assumed that with elimination of two double bonds, a ring 
has been formed, as suggested by the high density, 
77 
