CH. VIT.] TRACES OF FLOODS. 299 



though the latter contain hollows and gullies, which must 

 in wet seasons conduct water to the plains. The dis- 

 tance of such heights from the river, is seldom less than 

 twelve miles; and it would appear, that the intervening 

 country is of such an ahsorhent nature, that any water fall- 

 ing in torrents from the hills, is imbibed by the soft earth, 

 or is received in the deep broad cracks, which sear the 

 hollow parts, and in wet seasons must take up much water 

 and retain it, until either evaporated, or sunk to lower levels. 

 The water may thus be absorbed and retained for a con- 

 siderable time, or until it is carried by slow drainage into the 

 river, especially where the lower parts of such plains are 

 shut in by hills approaching the channel. Thus, where the 

 extremity of Dunlop's range shot forward into the wide 

 level margin, we found that the water had lost all taste of 

 salt, a circumstance most easilj^ accounted for, by supposing 

 that springs being more abundant there, from the near vici- 

 nity of the hills, had diluted the water which we had found 

 salt higher up. That some tributary, or branch joins the 

 river from the opposite bank, at or near the sweep it de- 

 scribes round the hill, is not unlikely. I could not conve- 

 niently examine that part from our side, and hence it 

 remains doubtful whether the problem admits of such easy 

 solution. 



The marks of high floods were apparent on the surface, 

 frequently to the extent of two miles back from the ordinary 

 channel. Within such a space, the waters appear to over- 

 flow and then to lodge in hollows (covered with polygonttm 

 jwicevm), and which were at the time of our visit full of 

 yawning cracks. Such parts of the surface would natu- 

 rally be the first saturated in times of flood, and the last 

 to part with moisture in seasons of drought. I observed 

 that there was less of that kind of low ground, where the 

 water was saltest, which was to the westward of D'Urban's 

 group. 



The 'basin of the Darling, which may be considered to 



