Ill 



values of x 2 and so on. The above tables show this 

 also to be the case, allowing for errors of experiment. 

 And it is caused by this circumstance, that the difie- 

 rentialequation for the velocity of reaction has obtained 

 the form, indicated above. 



In the later series K stands for = = 0,045. It follows 

 from this that with an increase of the temperature of 

 18,0 C K increases in the proportion 1:4,3. This cor- 

 responds to an increase of K in the proportion 1:2,2 

 with an increase of temperature of 10 C. 



The variation with the temperature of this velocity 

 of reaction is thus of the same magnitude as that of 

 the other velocities of reaction, dealt with above, as 

 well as of the velocity of chemical processes generally. 



Although the above equation is exceedingly simple 

 and of a quite empiric nature it shows at 24,5 (the 

 temperature of the room during the experiment) an 

 excellent agreement between calculation and observa- 

 tion. At 6 they do not agree so well; the velocity ot 

 reaction seems to decrease to some extent with the 

 increase of time. This is probably owing to the tem- 

 perature of the ice safe not having been completely 

 constant --it varied rather irregularly between 4,5 and 

 7,0 C during the lime of experiment Besides it is prac- 

 tically impossible to avoid heating the solutions while 

 handling them, this caused the velocity of reaction to 

 be greater at the beginning than later on. 



It may also be thai the empiric relation is not valid 

 with the same exactitude for this long times of reaction 

 (I 125 min). 



At all event this relation is very curious from a 

 chemical point of view and it is rather useful for prac- 

 tical purposes. The most curious thing about it is, that 

 it is true of the reaction from the very beginning, 



