522 Prof. R. Meldola on the Theory of the 



be p-nitrodiazobenzene-chloride and m-nitraniline ; along cd, 

 the products would be m-nitrodiazobenzene-chloride and p- 

 nitraniline. As a matter of fact all four products are obtained, 

 so that decomposition must take place in both directions. The 

 same explanation obviously applies to the mixed decompo- 

 sition-products of the ethyl-derivative. Again, the formula 

 shows the presence of the one replaceable H-atom in combi- 

 nation with the N-atom which is attached to the aromatic 

 radicals. The question of the existence of more than two 

 isomeric alkyl-derivatives will be considered subsequently. 



The formula which has now been suggested for the mixed 

 diazoamido-compounds derived from p- and m-nitraniline 

 can be applied with equal success to all other mixed com- 

 pounds. Thus, to take examples of those compounds whose 

 products of decomposition have been studied : — 



,N:Fl "- • N " :N " 



V'^' 



^>0 7 H 7 



6 ^\ 





H 



*^4 





H 



C 6 H 4 .C0 2 H 



Both these compounds were discovered and their decompo- 

 sition products studied by Griess : the first is obtained by the 

 action of diazotized aniline upon p-toluidine, or of diazotized 

 p-toluidine upon aniline ; the second is similarly produced 

 from aniline and amidobenzoic acid. When heated with acids 

 the first compound gives a mixture of aniline, p-toluidine, 

 phenol, and p-cresol (Nolting and Binder) * ; and the second 

 compound under similar circumstances gives aniline, phenol, 

 oxy benzoic, and amidobenzoic acid (Griess). The products 

 in these cases indicate separation along both planes of decom- 

 position a b and c d. 



The explanation of the existence of more than two isomerie 

 alkyl-derivatives of mixed diazoamido-compounds is closely 

 connected with the question whether the new formula can be 

 applied to the normal diazoamido-compounds. The following 

 considerations will show that these compounds cannot be for- 

 mulated on the new type : — 



As a type of the normal compounds let us consider that 

 derived from p-nitranilins (No. 2 in the table). If this had 

 the new formula it (and its ethyl-derivative) would have to 

 be written: — 



* This compound reduces to phenyl-hydrazine and p-toluidine, thus 

 indicating a preference of the N 2 - (and therefore the NH-NH 2 ) group to 

 remain attached to the more positive radical. The separation is in this 

 case along a b only. 



