420 



Mr. W. H. Pendlebury and Miss M. Seward. 

 Table XIY. " 



We see from the above tables that the ratios vary with the differ- 

 ences between the successive temperatures. They are, however, quite 

 independent of the quantity of each substance present. This is clearly 

 shown in the following table, in which the rates obtained with varied 

 quantities of potassium chlorate at 25 and 30 are compared. It 

 will be seen that the ratio is constant. A similar result was obtained 

 with varied quantities of potassium iodide, the ratios in this case also 

 being independent of the amount. 



Table XY. 



It will be seen that the rate almost doubles itself for the rise 

 of 5 between 25 and 30 in the above instances. 



A great number of experiments were made in which the tempera- 

 ture was varied by successive differences of 3, or 2, or 1 ; but the 

 numbers observed could not be considered quite satisfactory owing to 

 the intrusion of experimental errors, so it was generally found advis- 

 able to increase the temperature 5 at a time, thus making a marked 

 difference in the rate. We deduce from this result the average value 

 of the coefficient or ratio for the variation in temperature of 1. 



