aio Specific Gravity of Soluble Salts by 



As we shall see later, this irregularity is due to a specific 

 peculiarity of the caesium salts. Meantime it may be noted 

 that the volumetric equivalent of one gram-molecule of any of 

 the salts of the ennead varies from 2-124 H 2 O to 3-204 H 2 O, 

 the iodides having the highest and the chlorides the lowest 

 equivalents. The average difference between the volumetric 

 equivalents of the iodides and bromides is 0-563 H 2 O, and that 

 between the bromides and chlorides is 0-343 H 2 O. 



The Mother-liquor. The values of T are the same for 

 the mother-liquor as for the crystals, and are presented in 

 Table IV (a). In Table V (a) we have the values of m or the 

 molecular concentration of the mother-liquor. This is expressed 

 in gram-molecules salt per 1000 grammes water. It represents 

 also with great exactness the solubility of the salt in water at T, 

 and we shall consider it for a moment from this point of view. 



TABLE V. The Salt in Mother-liquor. 



(c) Values of - 



ffl 



31-223 38-069 49-021 Cl 

 39-038 44-I3I 48-I37 Br 

 49-506 58-575 67-907 I 



(d) Values of -|- 



low 



1-735 2-115 2-723 Cl 



2-169 2-452 2-674 Br 



2-750 3-257 3-773 I 



The least soluble of the nine is caesium iodide, which has 

 the highest molecular weight, and potassium chloride, which 

 has the lowest molecular weight, comes next to it. Next to 

 caesium iodide, in molecular weight and in solubility, we have 



