116 CHEMICAL STATICS 



It is curious that during the discussions which immediately 

 followed these discoveries the fact should have been so generally 

 overlooked that the above hypothesis of Whetham's is simply 

 a statement, in kinetic terms, of the Guldberg and Waage mass- 

 law. According to this law, the velocity with which any given 

 reaction proceeds varies directly as the active masses of each 

 of the reacting molecules. In the case under consideration, 

 presuming that a given number (e.g., one) of molecules of protein 

 react with one molecule of a salt of a monovalent metal to form 

 a compound, then twice as many molecules of the protein may be 

 supposed to react with a molecule of a salt of a divalent metal, 

 and three times as many with a salt of a trivalent metal. Assum- 

 ing that the active mass of the colloid (the molecular concentra- 

 tion multiplied by the degree of dissociation) is the same in each 

 of these cases (which is also assumed in Whetham's theory) and 

 equal to A, calling the initial velocities of the respective reactions 

 Vi, V2, and Vs and the concentrations of the mono-, di- and trivalent 

 ions Ci, C2, and Cs, we have: 



Vi is proportional to Aci, 

 V2 is proportional to A'%, 

 Vs is proportional to A^Cs, 



whence it follows that if ?;i = 2^2 = ^^3 and the velocity-constants of 

 the three reactions are equal (which is also assumed in Whetham's 

 hypothesis) :* 



'-i:^:^::l:A:A^ 



Ci C2 C3 



and— , — and — , i.e., the dilutions of the mono-, di- and trivalent 



Ci ' C2 Cs 



ions at which combination proceeds with equal velocity are re- 

 lated to one another in the same way. Now in the experiments 



described above, - is defined as p, the precipitating-power of the 

 c 



salt, hence: 



Pi-.Pi-.ps: -A-.A-.A^, 



which is exactly the relation deduced by Whetham. The rela- 

 tions found by Schultze, Prost, Linder and Picton and others, 

 are, therefore, just as explicable upon the assumption that the 



* In the terminology of Whetham's hypothesis, the term "velocity con- 

 stant" would read "proportion of effective collisions." 



