THE ACTION OF NEUTRAL SALTS 



109 



solutions, such as osmotic pressure, viscosity, etc., while non- 

 electrolytes, like cane sugar, have no such effect. Since in these 

 older experiments the pH was not considered and since this fact 

 is of paramount importance, it seemed desirable to repeat them. 

 It was found that non-electrolytes, like cane sugar, have no 

 depressing effect on the osmotic pressure or the viscosity of gelatin 

 solutions. Solutions of gelatin chloride of pH 3.4 containing 1 gm. 

 of originally isoelectric gelatin in 100 cc. solution were made up in 

 various concentrations of cane sugar, were rapidly heated to 45 

 and rapidly cooled to 24. The time of outflow of the gelatin 

 solutions through a viscometer was measured immediately. In 

 addition the time of outflow of the pure sugar solution was also 

 determined at 24C. The ratio of the time of outflow of the 

 gelatin-cane sugar solution divided by the time of outflow of the 

 pure cane sugar solution was thus determined. The results given 

 in Table IX show that the ratio of viscosity of gelatin solution to 

 viscosity of cane sugar solution is not diminished by the addition 

 of cane sugar; in fact it seems, if anything, slightly increased if 

 the cane sugar concentration is above M/8. 



TABLE IX. INFLUENCE OF THE ADDITION OF CANE SUGAR ON THE VISCOSITY 



AND OSMOTIC PRESSURE OF 1 PER CENT SOLUTIONS OF GELATIN 



CHLORIDE OF pH 3.4 



Similar results were obtained in regard to osmotic pressure as 

 Table IX shows. 



This fact is one of the prerequisites for the validity of the 

 theory of membrane equilibrium, since only ions contribute to 

 the equilibrium conditions on opposite sides of the membrane. 



A second prerequisite is, that the addition of salts should have 



