- (in itself) shows normal dispersion, will likewise show ede 
in an indifferent Setremgee and vice versa. : 
“form of the dispersion ratio curve of the esters examined, is inet Hee ees 
— 
power, it is essential to know the rotation dicpersion as accurately pk 
is not altered by the number of groups in the molecule. k, Sa, pines er 
Gptically active Bou the Tollowine proposition Fis weld ae 
already been shown that a change in constitution. produces a change 
position of the dispersion curve. Further it is known that the solvent ha 
on the rotation dispersion of dissolved substances. No definite tule as to h 
of the solvent can be formulated at eae In the case oF the meters in het 
parent substance and its derivatives have ions with the same branch, penile 
other words 4 will be constant. For the activity coefficient. kj, the rule” holds. tha rs 
position of the atomis in space and on their mutual distances, 
between the distances of the various. groups and the inoleealae dismeatees ie 
volume). If by some change in the molecule this relationship is disturbed, the 
coefficient also is altered. Poa 2 2a 
. 
other hand, the magnitude of the specific rotation is differently influenced by 
From acetosuccinic acid three menthyl esters can be prepared, whose rotatory 
is in good accord with their constitutional formule. Via introduction: of the dij 
methane residue in the menthyl ester of acetoacetic acid, the (d-+7) und a+ 
are formed. The (d-+/) form shows a complex anomaly, the dtp) like the 
acid disperses normally. In the yA of Dena ace tee ester the 
ester) show great irregularity in the complex anomaly of rotation dispersio 
solution. ales 
On the. basis of the latest reports, Rupe adduces the following 
1) Liebig’s a 420 (1920), 1. — %) ee 2: 
