ON THE STEREOCHEMISTRY OF NITROGEN. 185 
Na, b c X, and also two of the type, N abcd X—namely, methyl-ethyl- 
propylamine hydrochloride, and methyl-ethyl-propyl-isobuty] ammonium 
chloride—to the action of Penicilliwm glawewm. In the last case only the 
solution acquired a small but fugitive rotatory power of 0°4°-0-5°; the 
absence of activity in the other case was attributed to mobility of groups. 
This result has been contradicted by Marckwald and Droste-Huelsdoff,! 
but reaffirmed by Le Bel, with the addition of further details.” 
Wedekind * made several unsuccessful attempts to resolve the a phenyl- 
benzyl-allyl-methyl ammonium iodide, which was successfully resolved by 
Messrs. Pope and Peachey ‘ by crystallising the camphorsulphonate from 
non-hydroxylic solvents (acetone and ethyl acetate). The active com- 
pounds were then more fully investigated by Messrs. Pope and Harvey.’ 
The d-camphorsulphonate of the d-base had the molecular rotatory power 
M]p>=218° in dilute aqueous solution, the corresponding J/-1 salt had 
M]|>= —211° and the iodides had [M],, about + 200° in chloroform. 
The writer® also succeeded in resolving phenyl-benzyl-ethyl-methyl 
ammonium iodide in a similar way. The d-d and /-1 camphorsulphonates 
had [M]=+71°. The difference between the values of [M], for the 
basic ions in these two cases, namely 160° (approximately), and 19°5° caused 
by the replacement of the allyl by the ethyl! radical, is remarkable. 
A number of other active compounds are now being examined by 
Miss M. B. Thomas and the writer with a view of investigating the effect 
of substitution on the rotatory power. In the series containing the radicals 
phenyl, benzyl and methyl with propyl, isopropyl, isobuty1, and isoamy] the 
rotatory power appears to increase with the molecular weight of the last- 
mentioned radical, and in the last case far exceeds that of the allyl 
compound. 
That the resolution of ammonium compounds does not always take 
place so readily as in the first case examined is evident from the writer’s 
experiments,’ and the unsuccessful attempts of Wedekind® to resolve 
p-tolyl-benzyl-allyl-methyl ammonium d-camphorsulphonate, a salt very 
similar to that first resolved. 
So far no cyclic ammonium compounds have been resolved, though 
both « and (3 substituted pyridinium and piperidinium derivatives, and 
tetrahydroquinolinium compounds should be capable of giving rise to optical 
activity.° 
All attempts to obtain optically active compounds of the type Na, bc X 
have also been unsuccessful. Thus the writer ‘° examined a number of such 
compounds, Messrs. Kipping and Barrowcliff ! examined some piperidinium 
compounds, and Aschan !? tried to resolve the N-N ethylene-trimethylene 
dipiperidinium compounds, though not in an entirely satisfactory way, but 
in no case was there any indication of activity. Itis probable that all such 
compounds are planisymmetric, and therefore incapable of giving rise to 
optical activity. 
1 Ber., 1899, 32, 560. 2 Compt. rend., 129, 548. 
3 Stereochemie, 82. 4 Trans. Chem. Soc., 1899, '75, 1127. 
> Trans. Chem. Soc., 1901, 79, 828. 
® Trans. Chem. Soc., 1903, 83, 1418 ; 1904, 85, 223. 
7 Loe. cit., 1405. 
8 Zeit. phys. Chem., 1903, 45, 235. 
® Trans. Chem. Soc., 1903, 88, 1415. 
10 Loc, cit., 1903, 88, 1406. Cp. also Harvey, Trans, Chem. Soc., 1904, 85, 412. 
Loe. cit., 1903, 88, 1141. 12 Loc. cit. 
