10 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



FoRTHER Catalytic Experiments. 

 Fresh Violet and Green Solutions at 30°, 



These results contain much of interest ; their outcome is best seen in 

 the accompanying diagram. (Dotted curves H, B, and A.) The typi- 

 cal logarithmic curve whose inclination depends solely upon a constant 

 concentration of catalyzer and the changing concentration of the sucrose 

 is shown by the line A, representing the performance of the acid re- 

 corded in the last column above. Any departure from this curve must 

 indicate some other sujierposed reaction. 



Neither of the curves of the chromium solutions (B and H) shows pre- 

 cise similarity to the typical curve, but that of the green solution (B) is 

 of the same general character. Especially at first its irregularity is 

 slight; here it acts as if the concentration of its ionized hydrogen were 

 perhaps 0.095 normal. 



On the other hand the curve of the violet solution (H) indicates clearly 

 an important superposed reaction. At first, in confirmation of the pre- 

 vious results, it seems to contain about a tenth as much acid as the 

 green salt ; but the rate of inversion steadily increases with time, instead 

 of slightly decreasing. This anomaly is only to be explained by suppos- 

 ing the formation of more green substance and acid, — that is, by the 

 hydrolysis of the violet salt at 30°. This conclusion was verified by the 



* Thermometer reset. 



