178 Mr Reilly, The resolution of 
laevo-modifications certain cyclic ammonium compounds such as 
the a- and @-substituted pyridinium compounds or the tetra- | 
hydroquinoline derivatives of the type C,H,NR’R’X. These 
compounds should be capable of existing as optical antipodes 
since their molecules have no plane of symmetry (Jones, 7’rans. 
Chem. Soc. 1903, LXxxi1. 1400). In other cases it is thought that 
hydrolytic dissociation of the salts will account for the results 
obtained. In the particular compounds studied in the present 
work neither of these theories has been found sufficient. Similar 
solubilities of the two derivatives formed from the dextro- and — 
laevo-base and the optically active acid would seem to be a 
simpler explanation. This selective action of optically active 
acids, in their power to bring about the resolution of externally 
compensated compounds, noticeable much more frequently in the 
case of nitrogen than of carbon derivatives, would suggest that 
the non-resolution in particular cases is due to some other causes 
than those indicated. 
The present work was undertaken in order to investigate more 
fully this selective action of optically active acids. The original 
quaternary iodide resolved by Pope and Peachey (Trans. Chem. 
Soc. ibid.) is readily obtained in the dextro- and laevo-forms by 
fractional crystallisation of the d- and /-8-camphorsulphonates of 
the inactive ammonium base and reformation of the iodides by 
the action of aqueous potassium iodide. If a-bromocamphor- 
m-sulphonic acid is substituted for @-camphorsulphonic acid in 
the above experiments, a similar separation 1s much more difficult 
to obtain on fractional crystallisation of the a-bromocamphor-7- 
sulphonate. ‘To ascertain if racemisation sufficiently accounts for 
the different behaviour of the @-camphorsulphonates and the 
halogenated compounds, an attempt was made to obtain the pure 
dextro- and laevo-compounds of the base with dextro- and laevo- 
a-bromocamphor-7-sulphonic acid by an indirect method and so to 
test the hypothesis by actual experiment. 
By the reaction of anhydrous silver d-a-bromocamphor-7- 
sulphonate with d-benzylphenylallylmethylammonium iodide in 
dry acetone under certain conditions the compound, d-benzyl- 
phenylallylmethylammonium d-a-bromocamphor-7-sulphonate, was 
obtained in a pure form. 
By combination of the dextro- and laevo-iodide with silver 
dextro- and laevo-a-bromocamphor-7-sulphonate under different 
conditions the following compounds were obtained: dBdA, dBlA, 
IBIA and IBdA. 
Preliminary study of these compounds has shown that they are 
of the same order of stability as the corresponding §-camphor- 
sulphonates and show only a very slight tendency to racemise. 
A solution of 0°1655 grams of d-benzylphenylallylmethylam- 
