on the Physical Properties of Compounds. 121 



Note. — When all the side chains are of one kind the form 



is the most symmetrical, and always has the highest melting- 

 point. Bnt when the side chains are not all of the same 

 kind, then there seems to be a struggle between the three 

 forms 



AAA 



and between 



V 



X 



X 



and 



XII. 



Pentaderivatives of Benzene. 

 CH 3 CH, Me 



Br 



Br 



Bi 



Br 



Br 



Br 



Br 



m.p. =116. 



Br 

 m.p. =111. 



Br/ \bv 



Br 

 m.p. = 107. 



