ALUMINIUM HYDROXIDE BY ELECTROLYTES. 



9 



the wider tube of the viscosimeter, and mixed thoroughly. Then 

 the mixture was sucked up into the bulb. The measurement 

 of the time of flow was repeated several times with one and the 

 same mixture, and the mean was taken. As a rule single deter- 

 minations did not differ by more than a second. Between two 

 observations with different mixtures the apparatus was heated 

 with concentrated sulphuric acid, washed thoroughly with distilled 

 water, and dried. 



The following details of a series of observations made Avith 

 potassium sulphate as electrolyte will give an idea of how the 

 work was carried out. 



TABLE 1. 



The viscosity of the aluminous solution, containing 0.05 9o 

 of alumina and free from electrolyte, differed but slightly from 

 that of pure water. If we take the ratio of the time of flow 

 of various mixtures to that of the solution to which no electrolyte 

 has been added we get relative viscosities yj. 



