PROBLEM OF THE GREAT AUSTRALIAN ARTESIAN BASIN. 167 



partly for this, but for other reasons as well, it would seem 

 not unlikely that from deep-seated sources have been con- 

 tributed waters charged with carbonic acid and also sodic 

 carbonate. 



Gregory has laid stress upon the presence of small 

 amounts of boric acid in quite a large proportion of the 

 New South Wales waters, and this substance is probably 

 more widely spread, only it has not been looked for. He 

 has regarded this radicle as pointing towards a magmatic 

 origin for the water, and certainly Pittman's contention, 

 that its presence is not peculiar, because borates would be 

 contained in salts derived from sea- water by evaporation, 

 is ineffective, because the Jurassic beds are admittedly of 

 fresh-water origin, a conclusion supported by the scarcity 

 of such compounds as sulphates, chlorides and bromides of 

 magnesium. In citing F. W. Clarke on the marine origin 

 of the borates at Stassfurt, Pittman should also have quoted 

 this authority's conclusion, that in a large number of 

 instances boric acid is undoubtedly directly of volcanic 

 origin; Clarke has also noticed that in such cases there is 

 the frequent accompaniment of ammonia. Without wishing 

 to attach undue weight to the presence of this base, which 

 would naturally be in very small quantity, it ought not to 

 be overlooked that a good number of Queensland and a few 

 New South Wales bores have free, as distinguished from 

 albuminoid ammonia, in noticeable amounts, for instance 

 Normanton and Dillahlah No. 2. 



VI. The Gases Contained in the Waters and their Origin. 



Of the gases evolved from bores — methane, nitrogen y 

 carbon dioxide, and occasionally a little oxygen — the first 

 mentioned has been observed in a few cases, e.g., Thurloo, 

 Yowie, Baroma and Currumbah in New South Wales, in 

 Coonanna and Yandama in South Australia, but it is in 

 Queensland that inflammable gas is most frequent, e.g., 



