190 REPORT—1904. 
Secondly, it is assumed that, addition having taken place as before, 
the radical X then changes its position with the hydrogen atom at the 
apex of the pyramid, thus giving rise to a compound with the con- 
Fig. 9. 
ZN, 
figuration (fig. 9) which would be one of the isomerides, while the untrans- 
formed addition product would be the other (fig. 5 or 6). 
On this view one isomeride (the untransformed product) is devoid of 
a plane of symmetry, whereas the other is planisymmetric, one should 
therefore have an activity due to the nitrogen atom, and this might 
account for the abnormal rotatory power of the salts of the £ series. 
This view will account (a) for the existence of one isomeride of Na,bcX 
and its optical inactivity, since the original addition product (fig. 10) changes 
Fi@g. 10. Fie. 11. 
x 
x 
a 
into a planisymmetric compound (fig. 11), and (6) for the inactivity of 
piperidinium compounds, which would be represented thus: 
Fia. 12. Fig. 13. 
b CH, b CH, 
\CH, “\CH2 
: : 
CH Xx CH3— a | 
CH>----------- 4CH2 CH}----------- SoH, 
the plane of the piperidine ring being supposed perpendicular to the plane 
of the paper. 
A difficulty arises with regard to compounds of the type, NabedX, 
since they can be represented as giving rise to isomerides or not, accord- 
ing to the position which the new radicals are supposed to take up with 
reference to those already present. 
