44 



begiiiniiig and at llie end of every series llie electrolyte-free mixture 

 was measured, and vviien lliere was a diflfei-eiice, a correction was 

 applied to tiie intermediate values. The measurements have been 

 performed in an Ostwai.d viscosimeter ') and at 25°. 



In the subjoined tables the concentrations given are end-oonceri- 

 trations, the viscosity of benzene is put at 1.Ü00, »je 's the viscosity 

 of an electrolyte solution, ijs+e fiat of a rubber sol with equal 

 electrolyte concentration. The relation of these tiiiantities is given 



under -^, after the said correction for the lime reaction has been 



applied. 



TABLE I. 

 Influence of benzoic acid on ttie viscosity of rubbersols. 



In fig. 1 these result* are represented graphically. Corresponding 

 determinations have been carried out with acetic acid, hydrochloric 

 acid, sulphuric acid, sulphuretted hydrogen and mercury chloride. 

 Essentially the results are the same, the viscosity reducing action 

 alone is different; most for hydrochloric acid, in which already 

 1'/^ mMol per litre reduces the viscosity from 1,573 to 1,486 



Ammonia shows a very remarkable behaviour; the results are 

 recorded in table 11. 



1) With observance of all precautions according to H. G. Bungenberg de Jong, 

 Rec. Trav. chim. Pays Bas 43, 1 (1923). 



') Interpolated between the values for and 48 mMol per 1. 



