VELOCITY OF SAPONIFICATION 137 



Assuming that it is essentially the negative hydroxyl ion 

 that acts here, the process would be 



ZOA + (HO) = (ZO) + HO A, 



so that the hydroxyl combines with the alcohol radicle (A), 

 and its negative charge is transferred to the acid ion (ZO). 

 On saponification by acids the attack is between the 

 acid radicle and the oxygen. Assuming that here it is 

 essentially the positive hydrogen ion that acts, the process 

 would be 



so that the hydrogen ion combines with A and transfers 

 its charge to the hypothetical residue Z, which then by its 

 action on water reproduces the hydrogen ion, 



(b) Other Spatial Influences J . 



In dealing with the problem of velocities two distinct 

 points of view may be made use of. From the first the 

 necessary relations between equilibrium and velocity, and 

 between the former and temperature, lie in the foreground. 

 The practical execution of the problem is then very com- 

 plicated and lengthy ; but, on the other hand, the certainty 

 of the basis facilitates any test of a supposed bearing 

 on constitution. Otherwise the velocity may be simply 

 determined for as many reactions as possible, thus sub- 

 stituting a wide extent of data for certainty of theoretical 

 basis. The connexion between the two principles lies in 

 determining the conditions under which the reactions in 

 question run their normal course in time, and whose 

 velocities may, therefore, be exactly expressed by velocity 

 constants. 



With the data at present available it is only possible 

 to bring forward some general results and refer these to 



1 Scholtz, Einfluss dcr Raumerfullung der Atomgruppen. Sammlung von 

 Ahrens, 1899. 



