RICHARDS AND BONNET. — DISSOLVED CHROMIC SULPHATE. 11 



or 



0.6^ 



0.6' 



0.4' 



0.3' 



0.2' 



O.V 



10 



20 



40 



50 



00 



Figure L — The Results of Catalysis. 



Hours are plotted abscissally, and changes in the freezing point ordinately. 

 The curve A corresponds to pure acid, B to freshly boiled green solution, // to 

 freshly made violet solution, and E to both of these solutions after having been 

 kept for a month at 30°. 



color of the solution, which at the end of five days had become decidedly 



green. 



This series of experiments thus showed the following facts : — 



First, the green salt hydrolyzed at 50'^ contained slightly less acid 



than that hydrolyzed at 100°, the respective acidities being perhaps 0.10 



and 0.13 normal in a | molar solution. 



