Feb., 1919] Salt, Iron, and Acidity of the Ash 



229 



from the slopes of Katmai, shows a relatively high water soluble 

 content, 39.2 parts per 100,000. This finely divided, compact 

 layer does not leach out so readily as the coarse material of the 

 lower layers, and consequently will hold its salt content more 

 tenaciously. 



A comparison of the total water soluble salt content, as deter- 

 mined by the Electrical Bridge, with the ferrous iron content, as 

 determined by successive leachings and titration with KMnCX, 

 shows a wide divergence in the cases of Sample 33 and the 

 Pillar Mountain drift. The total water soluble content does 

 not nearly approximate the ferrous iron content as calculated 

 from the reducing property of the leachings. This would 



TABLE II. 



SOLUBLE SALT CONTENT OF KATMAI ASH. CALCULATED FROM THE ELECTRICAL 



RESISTANCE. 



indicate that the ferrous compound, whatever it may be, 

 either does not go readily into solution or does not dissociate. 

 The agreement between the results in the case of the remainder 

 of the samples included in Table I and those in Table II is 

 much closer. Although a considerable range of water soluble 

 salt content in the various samples of ash is seen to exist, yet 

 the divergence from that of a normal soil is not so marked as 

 one might expect, the content from the normal soils listed lying 

 intermediate between the extremes of the ash samples. Even 

 the high water soluble salt content of (1), (5), (6) and (7), 

 in Table II, is not so high as that of some alkali soils on which 

 crops grow and mature. 



