46 



Transactions. 



In Table I are collected the melting-points of the anilides 

 and paratoluidides. It is seen that the numbers do not form 

 a regular series, but vary in a most erratic manner, the irregu- 

 larities being greatest among the earlier members. In the 

 case of the even members a regular increase in the melting- 

 point is observable after the tenth member, and, further, the 

 differences between the two sets of numbers gradually 

 diminish. 



* Determinations by the author. 



One of the causes of these abnormal results is probably 

 the symmetry of the molecule, which has been shown in many 

 cases to have a great influence on the melting-point. Hence, 

 if in two series of compounds of similar nature symmetry in 

 one case tended co reduce the melting-point, and in the other 

 to cause an elevation, the possibility arises that these two 

 factors might balance each other ; consequently, on adding 

 the melting-points together a regular series might result. 

 This method of treatment has proved to be successful, and 

 satisfactory results have been obtained, more especially in the 

 case of the even members, for which the data are more com- 

 plete. 



A series of such a nature is that of the fatty amides, the 

 melting-points of which tend to rise or fall as the correspond- 

 ing numbers in the case of the anilides or paratoluidides 

 diminish or increase. The values obtained by adding these 

 series together is given in Table II. 



