ARTICLES 417 



Of interest is the attitude of the Armstrongs (191 3) with 

 regard to the action of electrolytes. These investigators stated 

 that action could never take place between non-electrolytes, 

 and it was therefore assumed that the electrolytes themselves 

 acted by bringing about the inclusion of the interacting sub- 

 stances H or OH in the electric circuit, and that the changes 

 themselves take place as soon as the circuit is established. Such 

 an assumption is included in the hypothesis put forward by 

 them that enzymes have a double function, that of attracting 

 or holding the electrolyte in adsorption, and that of deter- 

 mining its hydrolysis ; in other words, that the enzyme retains 

 the hydrolyte in the circuit while hydrolysis is effected through 

 the agency of an electrolyte itself possibly formed from the 

 active radicle of the enzyme. The full hypothesis, which 

 includes a theory as to the constitution of enzymes, is too long 

 to deal with here. 



Palladin (191 6) reached a conclusion similar to that of the 

 Armstrongs : he found that non-electrolytes stop the action 

 of the proteoclastic enzymes in plants, and suggested that 

 the action was due to a change in the electrical conductivity 

 of the system. He also suggested, however, that the 

 action might be due to a change in the hydration of the 

 proteins ; and it is along this line that recent work on the 

 subject tends. 



Reference has already been made when dealing with H* ion 

 concentration to the work of Ringer (1916), who drew attention 

 to the relationship between the action of salt and the swelling 

 of albumin. 



Some explanation for the swelling of protein was put forward 

 by Pauli in 19 12. He considered that electrolytically dissoci- 

 ated salts of protein are formed by acid and alkali, and that 

 the swelling is due to the affinity of water for the protein ion. 

 It is supposed that the effects of salts in removing water is 

 exerted rather on the water itself than on the protein. Pauli 

 also pointed out evidence that a surface action is in question, 

 in that the viscosity of protein solutions is always lowered by 

 the addition of a salt. The actual process may, as stated by 

 Posnyak (191 2), be due to a simple solution of the liquid in the 

 substance of the particles, which thereby change their shape 

 and size, to a filling-up of capillary spaces between the particles 

 of the protein as a result of condensation of water on them, or to 

 a combination of both processes. Zigismondy (191 3) considered 

 the second process to be more important. 



The possibility of a change in the concentration of the H' ion 

 has also to be considered. Falk and Nelson (19 14) showed that 

 the addition of sodium chloride to a solution of hydrochloric 

 acid caused an increase in the H* ion concentration, as estimated 



