m 



Propyl- Cyanoacetate. 



du. 



dl 



in Erg. 



Temperature-interval: 



between - 16° and +152^ 1,88 



Then an increase: 2.13^ under dissoci- 

 ation and liberation of HCN. 



Isobutyl-Cyanoacetate. 

 between —20° and 0^ 1,64 



0^ „ 115^ 1,70 



115° „ 213^ 2,0 

 Gradual decomposition, under liberation 

 of HCN. 



Butyl- Cyanoacetate. 

 Temperature-interval : £ in Erg. 

 between —21° and +213° 1,62 



Amyl-Cyanoacetate. 

 between —17° and + 1° 2,0 

 1° „ 201° ca. 1,6 



Carbontetrachloride. 

 between —18° and 0^ 2,6 



0° 

 25° 



25<^ 

 55° 



1,95 

 1,75 



Evidently only in some cases the coefficient — appears to be really 



constant; in most cases it decreases doubtless with a rise of tempe- 

 rature. Where the inverse behaviour was stated, a decomposition of 



du 

 the studied substance always seemed to occur. The value for — • 



^ dt 



is in the interval of ordinary temperatures relatively small for propyl- 



and isohutyl-alcohol and for the cetones; however in these cases it 



appears to be variable with the temperature in no higher degree 



of* 

 than in the cases, where the values of t— do not differ largely from 



Ob 



2.0 Erg. 



Groningen, June 1914. Laboratory for Inorganic Chemistry 



of the University. 



