INTRODUCTION 



figures with observed ones is of a greater use and 

 clearness. 



But we can proceed more simply by putting 

 y = log , i.e. plotting log z as a function of /, in 

 which case we get a straight line (the continuous 

 line in Fig. 2), beginning at the point j)' = log = 

 log 1 00 = 2 and cutting the ^-axis in the point log z 



too 



80 



t 



z 



60 



40 



20 



\ 







\ 



\ 





0-, 



20 



16 



t 

 Log 2 



12 



08 



04 



FIG. 2. 



= 0, i.e. z= i, and 2o = bt Q , i.e. t Q = 2Jb (in Fig. 2 

 /= 20-6, / lies so far to the right that it does not 

 appear in the figure). Here the value of b is 

 very simple, namely, 6=2/t , b is the so-called 

 velocity of reaction, it is equal to 2 divided by the 

 time in which the quantity of cane-sugar has sunk 

 to one per cent of its original value. Evidently 

 the shorter the time for decomposing 99 per cent 



