PfiOBLEM OF THE GREAT AUSTRALIAN ARTESIAN BASIN. 



161 



in many of the river waters of Queensland (see analyses in 

 I. App. pp. 52 - 63). 



In the preparation of the accompanying Isosaline Map 

 (Diagram II), only the amount of chlorides present (with 

 rare exceptions wholly that of sodium) was chosen for 

 plotting, for the following reasons : — 



(a) because of the fact that as yet the abstraction of com- 

 mon salt from percolating water is unknown to occur in 

 nature under the conditions normally met with here, (b) 

 because its proportion therefore can only be increased 

 and not diminished in time, and by the movement of the 

 water, and (c) because on the other hand the abstraction or 

 conversion of carbonates is both possible and probable. 



Diagram III. — Salinity of Waters ; figures represent grains of sodium 

 chloride per imperial gallon. 



K-July 4, 1917. 



