986 



Mr. Gervaise Le Bas on the 



Propyl. Maleate. 

 d 20 ' 1*02899 



Fumarate. 

 d 2Q 1*02203 



Ethyl Citraconate. 



CH 3 -C-COOC 2 H 5 



1 j 



Ethyl Mesaconate. 



COOC 2 H 5 -C-GH 3 



II 



HC-COOC 2 H 5 



HC-COOC 2 H 5 



d 20 (Knops)... 1-06241 



Solutio 



d 20 1-04674 



n Volumes. 



(Traube, Ann. 



240. p. 43, 1886.) 



Sodium. 

 Maleate. Fuinarate. 

 V 3B 54*3 A -5-1 59-4 



Citraconate. 

 Y 15 66-5 A... 



Mesaconate. 

 ... -4-1 70-6 



Crotoconate. 

 V15 62-4 A.., 



Isocrotoconate. 

 .... -2-0 64-4 



All these results are in favour of our view. The malenoid 

 compounds are marked by a contraction and a higher B.P. 

 than the fumaroid, similar, indeed, to what is shown by the 

 a and (3 di-substitution compounds. These features are 

 accompanied by the possibility of forming the ring com- 

 pound in the malenoid form — Maleic anhydride, Citraconic 

 anhydride. 



The above data are for 20°. No data exist for the B.P. 

 It must be remembered that the contractions are considered 

 to be the result of Residual affinity, and since the groups 

 — C . OOR are nearly saturated, the contractions may not be 

 large in these instances. 



It thus seems clear that the constitutions which we give 

 to the above geometrical Isomers, and which account for 

 certain peculiarities, must be given to the ^-derivatives of 

 the Paraffins, since similar physical peculiarities are shown. 



In carbon chains of greater length than two, curvature is 

 an additional fact which must be taken into consideration. 

 The tendency of the CI atoms, say, to approximate even in 

 ethylene derivatives, constitutes a curvature of the chain 



from C1-CH 2 -CH 2 -C1 to CH 2 -CH 2 



CI— CI 



