228 Proceedings of the Royal Society of Victoria. 



(ii.) Experiments at 50°-60°C. 



A solution was made up containing 15 molecules of KMnO^ to 

 1 of sugar, and placed in a flask immersed in water heated to 

 50°-60°. All the KMnO^ has not been reduced to MnO., at the 

 end of 2^ hours. 



The temperature was then raised to 80° and tbe remaining 

 colour disappeared in less than 20 minutes. 



As the action was so slow at 50°-60°, further experiments 

 were not attempted at this temperature. 



(iii.) Experime7its at temperatures above 80°C. 



From 80° to 90° has appeared to be the most convenient 

 temperature, for if colder the action is too slow, and if hotter, 

 then the secondary action has an appreciable influence on the 

 result. 



It will be seen from the table of results, that the reaction at 

 this temperature is practically complete in 1 hour under these 

 conditions of experiment. Experiment 4 is apparently incorrect. 

 The high values in Experiments 9, 10 and 11 are apparently 

 due to the secondary action being accelerated by the higher 

 temperature. The action is evidently not largely aflfected by 

 the quantity of acid present, when within moderate limits ; see 

 Experiments 2, 3 and 7. 



Table II. 



N. 



50ccs.^KMnO„ 



was employed in every case. 



The amount of sugar was arranujed so that the ratio of sugar mole- 

 cules to KMnO^ molecu.les originally present varied from l%-5%. 



