735 



to numbers 38, 45, an(i 46. These are the most weakly active, the 

 only ones where the value rose beyond 3 minutes and it is exactly 

 these samples that consist principally of sand. Besides these 3 samples 

 there are only two left (37 and 39) which also chiefly contain sand, 

 but these too belong to the least active ones. In 37, 38, 39, 45, 

 and 46 the layer of sand was ah'eady present at 60, 60, 60, 30, 

 and 30 cm. below the level of the sea. 



So here it is once more corroborated, that radio-active action 

 grows less according as the sample of the soil contains more sand 

 or organic substance. The curves in Fig. 2, when compared mutually 

 or with the above-mentioned particularities of the soils may demon- 

 strate clearly, that two very different methods have led to this same 

 conclusion. That sample 12 shows a surprising difference in the two 

 methods is very striking indeed. May be that it points out that the 

 very high number of sample J 2 in this series is yet of particular 

 importance. 



