280 Mr. G. 8. Walpole. The Action of [Oct. 22, 
-The residue from the distillation was dissolved in benzene, and fractionation 
by petroleum ether was continued. It became necessary at this stage to take 
the [«]p, as well as the melting point and weight of each crop, and these 
crops were then sorted out with respect to their optical activities. It fre- 
quently happened that when material that was considered inactive was 
further fractionated it yielded strongly dextro- and strongly levo-rotatory 
substances. The separation at each step was very slight, and a very large 
number of precipitations was required before any fractions which could be 
regarded as pure substances were obtained. 
The final products of this fractionation of the substances contained in the 
alcoholic mother liquors mentioned above were :— 
(1) A substance of [«]p about —50 in alcoholic solution, melting at 
145° C. The glycol obtained by hydrolysis was strongly dextro-rotatory. 
(2) A substance of [e]p greater than +34 and melting higher than 
200° C. 
These substances were not further examined, owing to the small amount 
obtainable in the pure condition, as judged by the definiteness of the melting 
point. One of them is possibly the diphenylurethane of an active 2 : 3- 
butanediol. | 
(3) A substance melting at 157°, and optically inactive in alcoholic 
solution. Analysis :— 
01056 grm. gave 0°2530 grm. COz and 0°0578 grm. H20. 
01120 grm. ,, 86 cc. N. at 12° and 723 mm. 
Bona Calculated for 
} C4HyO2(CeH;CNO)>. 
Cee ee 65-3 65-82 | 
HESS, 6-08 6 -09 | 
Nie 8 62 8°53 | 
e3 | 
03 grm. was taken and hydrolysed in the manner described below and the 
aqueous solution of the resulting glycol oxidised by bromine in the light. On 
distillation under a long column the characteristic yellowish-green ring of 
diacetyl was seen to come over and the material was found to possess the 
peculiar smell of diacetyl. The distillate reduced Fehling’s solution at once 
in the cold and yielded a crystalline osazone. The quantity was so minute 
that a melting-point determination could not be performed satisfactorily. 
The evidence obtained, however, was considered to prove that the inactive 
diphenylurethane melting at 157° gave on hydrolysis a butanediol which 
ae Se 
