8 



Conductivities and Viscosities in Pure and in Mixed Solvents. 



TABLE 1. Viscosity ami Fluidity of Ccesium Salts in Mixtures of Water with Methyl Alcohol, 

 Ethyl Alcohol, and Acetone at 15, 20, and 35 Continued. 



DISCUSSION OF RESULTS. 



As can be seen from table 1, measurements have been made of 

 the viscosities of solutions of these salts at 15, 25, 35 in mixtures 

 of 25, 50, and 75 per cent of each of the three solvents with water. 

 Caesium salts, with the possible exception of the carbonate, are prac- 

 ticalty insoluble in the alcohols and in acetone; and in a number of 

 cases it was impossible to obtain solutions more concentrated than one- 

 fourth normal in the 75 per cent mixtures. In fact, caesium nitrate was 

 not more soluble than tenth-normal in 75 per cent methyl alcohol and 

 75 per cent acetone, while it is impossible to obtain even that con- 

 centration in 75 per cent ethyl alcohol. One peculiarity previously 

 noted in the case of rubidium chloride in 75 per cent acetone was also 

 observed with caesium chloride. A one-half normal concentration of 

 this salt could easily be prepared, but with a partial separation of the 

 acetone from the solvent. However, on cooling below 10 a perfectly 

 homogeneous mixture again resulted, which separated again into two 

 layers on warming. The nitrate at this concentration merely remained 

 partially undissolved. The results obtained are tabulated for each 

 salt under the heads of the different solvent mixtures, the blank 

 spaces indicting that the salt was insoluble at the concentration in 

 question. In general, both of the salts lower the viscosity of water and 

 of the 25 per cent mixture of all the solvents, and increase the viscosity 



