446 TRANSACTIONS OF SECTION B. 
vapour at various volumes, using quartz apparatus and the quartz membrane 
manometer devised by Gibson." é : 
The vapour density corresponds to the formula P, up to about 700° C., above 
which dissociation takes place according to the equation : 
Payee 
There is no evidence of further dissociation at the temperatures investigated. 
The law of mass action applied to the new measurements decides against the 
equation : 
1 apg egled 2 
The authors desire to thank Dr. Erich Stamm for valuable assistance in the 
course of the research, and to acknowledge receipt of a research grant from the 
Carnegie Trust, from which part of the expense of the investigation was defrayed. 
TUESDAY, SEPTEMBER 10. 
Discussion on the Migration of Groups. 
The following Papers and Reports were then read :— 
1. The Walden Inversion. By Dr. A. McKenziz. 
2. Interconversion of the Enantiomorphous Forms of Phenylmethyl- 
carbinol. By Dr. Auex. McKenziz and Grorce W. Ciovucu. 
Work on the Walden inversion has been hitherto confined practically entirely 
to changes undergone by carboxylic acids or their derivatives, esters, &c. In the 
present communication it is shown that an optically active alcohol can be trans- 
formed into its enantiomorphously-related isomeride by the aid of a Walden inver- 
sion. The following cycle can be effected :— 
(by SOCI ) 
C,H; H C,H. H 
d GH >’ < og Ss aie OCG 
(by Ag,O and water t | (by Ag.O and water 
or or 
by NaOH and water) by NaOH and water) 
C,H, H C,H H 
1 GHS>C<q. «-—— 1 - ct, > 8 Son 
(by SOCI,) 
On the other hand, the action of phosphorus trichloride on the d-carbinol is accom- 
panied by a change of sign of rotation and the resulting /-a-chloroethylbenzene is 
considerably racemised. 
Action of Thionyl Chloride on the Active Carbinols.—d-Fhenylmethylcarbinol was 
prepared by the resolution of the hydrogen dl-succinic ester by means of brucine 
according to the method of Pickard and Kenyon.” It boiled at 104°/23mm. and 
had [a'7” + 43°-36, a value in agreement with that quoted by Pickard and Kenyon. 
The d-alcohol (4 grams) was added gradually to thionyl chloride (10 grams). 
The product was distilled under diminished pressure and the fraction boiling at 
$5°/20mm. amounted to 4 grams. It had ap + 26°-90 (= 0-5), di° 1-0631, whence 
[a]*°+50°-6. Found Cl = 25-3; calc. 25-2 per cent. 
The /-alcohol, obtained by decomposing the mother liquors from the crystallisa- 
tion of the brucine salt of the hydrogen succinc ester, had a , —26°-70 (1 = 1): 41 grams 
was added as before to 56 grams of thionyl chloride. The fraction boiling at 
85° /20 mm. had [a}i? — 30°-15. Found Cl = 25-3; calc. 25-2 per cent. 
Action of Phosphorus Trichloride on d-Phenylmethyl:arbinol.—The d-alcokol] 
* Diss. Breslau, 1911. 2 Trans. Chem. Soc., 1911, 99, 45, 
