1538 
content of the citraconic and itaconie acids complexes) the mercury 
content of this compound is 67.0 °/ 
Hence, in the molecule of the cis-“labile”’ elutaconic acid, one of 
the mobile H-atoms of the methylene group would be substituted 
by mercury; this can very well be so, for also from the malonic 
ester and from the malonie acid itself (which also possess a very 
reactive CH,-group) similar simple mercurised derivatives have 
been prepared by Birtmann. Moreover, according to the investiga- 
tions of HenricH, the H-atoms of the methylene group in the glu- 
taconic ester are replaceable by metals. 
2. In the ea-dialkyl-substituted glutaconic acids there exists a great 
difference between the cis- and trans-forms as regards the velocity 
of the bromine addition. According to the researches of PERKIN 
and his co-workers the formation of the corresponding dibromo- 
elutaconie acid proceeded very readily with the cis-acids; when 
exposed in a thin layer to the action of bromine vapour the absorp- 
tion was complete in a few hours. On the other hand the trans- 
acids were either not at all or but very slowly attacked in 
this method. 
If now the “normal” glutaconie acid is exposed to the action ot 
bromine we can expect here via the cis-labile form a rapid assimi- 
lation of bromine. 
This expectation was not doomed to disappointment. Finely pow- 
dered glutaconie acid spread out in a very thin layer on a watch- 
glass and placed in a desiccator at the bottom of which was placed 
a layer of bromine, had practically absorbed the theoretical quantity 
of bromine in a few hours. 
The powder thus obtained was recrystallised from a little formic 
acid (D 1.21) or from chioroform. 
«3-Dibromoglutaric acid forms a white crystalline mass m.p. 152° 
readily soluble in water and ether, less so in chloroform and very 
sparingly in petroleum ether or benzene. The titration of the acid 
gave the following result: 
0.3040 gram required 22.23 ec. 0.0947 n. baryta: M = 289.2 
0.1954 „ 55 14.26 ce. zi 55 ee 289.7 
theory - M= 290.0 
A bromine determination gave: 
0.1632 gram of substance rielded@: 2121 erm. AgBr. Found : 55. 30"), Br 
theory « 55.15°/ Br. 
In aqueous solution, glutaconie acid also takes up bromine fairly 
