( 264 ) 



II. INFLUENCE OF THE SOLVENT. Temp. IS"— 25°. HYDROCHLORIC ACID. 



Alcohol and methyl alcohol alter the relation of the transformation 

 to the (lisathantage of the benzidine and the effect becomes g'reater 

 when the amonnt of water becomes less. This may be caused by 

 the circumstance that in another nie(Hum the reaction may take a 

 different course (foi" instance, the velocity- of the formation of diphe- 

 nyline may increase) but it is also possible that the deviation must 

 simply be attributed to the increased solvent action which dilute 

 alcohol exerts on hy(U'azobenzene or an intermediary product of the 

 reaction. It is not due to an increased solubility of benzidine sulphate 

 in dilute alcohol as has l)een proved in a purposely made direct 

 experiment. 



III. INFLUENCE OF THE KIND OF ACID. 

 a) Temp. 100°. Water. 



As at lOtr a small quantity of azobenzene or aniline may be 

 formed (the -formation of the latter has not been investigated for 

 the Aveak hydrochloric acid concentration) the figures for the forma- 

 tion of diphenyline would be valueless and they have, therefore, been 

 omitted in table III. Those for benzidine are probably a little too 

 low as the formation of azobenzene could not be entirely avoided. 



