of “spray electricity”. erate Kewise 
electricity”. No direct: relation peuwesn this phenomenon and ‘tt | 
of the different bodies could be traced, neither any such relation betw 
and the quantity of “spray electricity”. Ps 
phenomenon of Cotton?). a 
Their investigation dealt in the main with the four bodies ‘mentioned in the 
paper, 7. e., 2,6-dimethylundecatriene-2,8,10 (prepared from citronellal and magnes n 
a isibsotnide): 2,6-dimethyl-8-phenyloctadiene-2,7 (from citronellal and ‘magnesiumpher 
_ bromide), menthyl $-phenylcinnamate, and diphenylmethylenecamphor. — For sake  o} 
comparison, several other substances were also taken into consideration, which belong 
either to the same chemical series or were at least closely allied to them, ‘but other’ 
wise showed normal rotatory dispersion. Amongst these were: several menthyl esters \ 
then the hydrocarbons with normal optical rotation prepared from citronellal and Gr | 
nard’s salts which had been investigated by Rupe and Jager*), and several esters of 
myrtenol, which are all characterized by a decided normal and similar rotatory dis- 
persion, as had been demonstrated by the proceding paper. Furthermore, Aiphenylg 
camphomethane and some derivatives of methylenecamphor were examined. 
None of the substances investigated showed a selective power of absorption; 
cases, the absorption curve took a more or less continuous course. eae 
Amongst all substances hitherto examined, diphenylmethylenecamphor, a “ay of ; 
light-yellow colour, showed the highest degree of relatively abnormal rotatory dispersion. 
Diphenylmethylenecamphor may be prepared following the directions of Haller and o 4 
Bauer®); an easier method is the following: Sodium is added to a solution of camphor 
in dry toluene and heated until the metal is fused. Very soon, a vivid reaction takes 
place; the mixture is allowed to cool down in a current of hydrogen, then the tolu 
is decanted off and a solution of benzophenone in toluene is added, the whole shake 
vigorously and heated to 120 to 130°. Unattacked camphor, borneol, and toluene are the n 
removed by steam distillation and the residue recrystallized from alcohol: m.p. 113. 
given by Haller and Bauer as melting point for diphenylmethylenecamphor. Diphenyl- 
camphormethane melts, according to the same authors, at 106 to 1079; senaTa I 
prepared samples showed different optical rotation. My 
Rupe and Silberstrom found for the two bodies prepared according tee ‘the ’ 
methods described by Haller and Bauer the identical melting point 135.5 to 136. 5° anc 
nearly the same dextrorotation. For the first, it could not be stated with certainty v wt 
is the reason for the great difference in the behaviour of the bodies prepay by. 
and Silberstrom and by Haller and Bauer. E 
1) Liebig’s Annalen 409 (1915), 327; Report October 1915, 63. — %) Liebig’s Annalen 414 
3) Comp. Berichte 44 (1911), 2023. — *) Liebig’s Annalen 402 (1914), 149; Report April 1914 
rend. 142 (1906), 975. F% ats en aie a 
