220 Journal of the Asiatic Society of Bengal. [N.S., XVII, 
(MI, Difference 
C=N ° 
Co Mg e oS 1774 
c=0 
Z 1506:5° 
CH: NH 
“a Ma ¢ os: 267-5 
at = 4G 1985 
8. | 1567-2 
c CH:NH 417-8 
eo <4 
In each of these eight sets of compounds the only change 
effected has been the addition of two atoms of hydrogen in 
the imino-derivative thereby breaking the conjugation. ‘The 
fall in rotatory power when conjugation is broken is simply 
omenal 
The effect of complete conjugation between carbon, 
oxygen, and nitrogen atoms with the benzene ring on [rotation 
is brought out very clearly in the meta and para phenylene- 
bisiminocamphors : 
[ri], 
C=N N= © isi 
oh <> ye H,---- 6096 
. ARs O=c nies 
and CONJUGATION BROKEN 
C=N -7 N=C © 
Se Mig 5 Oe Hy---- 2660 
6.214 c=o @ o=c 8 14 
The rotatory power of the p-compound is more than twice 
as large as that of the meta, and this is obviously due to 
uninterrupted chain: of conjugations in the molecule’ of 
P-plenylenebisiminocamphor, which, however, does not exist 
m the meta derivative 
Again p-phenylenebisiminocamphor 
C=N ‘- 
<8 Ha Oa Ge C. 8 
C=0 at 8 
(M], 5405° 
