Geology 



had gone, so we started for camp, some three miles 

 away. 



On the way in, the troglodyte told us that after we 

 had left him, he had the misfortune to drop the small 

 bag of black sand into the river, and so decided to 

 practise the motion with ordinary sand. This he con- 

 tinued to do for some time, and finally, in an absent- 

 minded way, was washing out the residue as slowly as 

 possible, so as to practise control of the movement, when 

 the sunlight happened to strike the edge of the little 

 heap of wet sand in the bowl and he noticed a thin 

 yellow line along its edge. Carefully continuing the 

 process he succeeded in getting rid of nearly all the 

 sand, and examining the " colour " with a lens was 

 satisfied as to its nature. We had missed the gold in 

 the first instance by introducing the black sand, which, 

 at the end of the operation, was left in sufficient quantity 

 to mask the metal. 



Needless to say we were up before the sun next 

 morning and at work at our digging as soon as the light 

 was strong enough, for although we had proved the 

 presence of gold, we had not yet ascertained whether it 

 was present in paying quantity. 



The accumulation of gold by stream action is similar 

 in principle to the process of panning. The lighter 

 quartz sand is swept away, while the heavy gold collects 

 in pockets or hollows of the stream bed. It very 

 frequently happens that the richest part of a deposit, 

 such as we had been examining, lies at the bottom where 

 the sands are in contact with the bed rock, and we 

 therefore set to work to dig down to this level. 



The gold in this case would appear to have been 



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