278 



REPORT — 1901. 



stage in the process of concentration so long as its presence is compatible 

 with that of the other salts ; moreover, it continually separates, and in 

 the natural deposits always accompanies the other salts. 



In representing the behaviour of solutions containing, in addition to 

 Sodium chloride, Magnesium sulphate and Potassium chloride — the salts 

 present in the case previously considered — to construct a diagram, as the 



Fig. 5. 





s \m]/'of)l 



composition of such a solution cannot be expressed in terms of fewer than 

 four salts, a fourth dimension would need to be introduced were it not 

 that, as Sodium chloride is always present, it may be represented in the 

 form of a sheet of varying thickness spread over the upper surface of the 

 model representing the composition of the various solutions in terms of 

 the other salts present ; to construct this sheet the number of molecules 



