Feb., 1919] Nitrogen Content of Volcanic Ash 



219 



as in (1) and (4). Sample 33, collected by Dr. Griggs in 1916, 

 was found to contain twice as much total nitrogen as (1)-, 

 in which seedling grass was growing, but the acidity and 

 ferrous sulphate content was so high as to preclude the pos- 

 sibility of plants surviving. 



Martin Creek, the principal affluent of Katmai River, 

 flows in from the west and brings the drainage waters from 



TABLE IV. 



Nitrogen Content of River Deposited Pumice and Ash, Katmai River, 



Martin Creek Camp. 



1917 



July 1. (1) River deposited ash, Lupintis noot- 

 katensis in blossom 



July 2. (2) River deposited ash, Lupintis noot- 

 katensis in blossom.. 



July 2. (3) River deposited ash, three foot 

 radius from (1) 



July 2. (4) River deposited ash, three foot 

 radius from (2) 



July 2. (.5) Mixed sample from around several 

 lupine roots 



July 2. (6) Mixed sample from around several 

 lupine roots 



Julv 2. (7) Sample of ash, etc., two feet be- 

 neath (1) 



July 2. (S) Brown humus soil, lupines growing.. 



Aug. 15. (H) Ash among roots of lupines, near 

 spring north of Martin Creek 



Aug. 15. (10) Ash among roots of lupines growing 

 farthest out on ash deposited by 

 Katmai River 



hxig. 15. (11) Ash around roots of ripened lupines. . 



Aug. 16. (12) Martin Creek, black sand, lupines 

 growing 



Aug. IG. (13) A.sh bed of creek below spring, near 

 trail, sickly grass seedlings 



Aug. IG. (14) Old soil surface, many plants growing. 



Parts Nitrogen per 100,000 



NH., 



0.02 



0.032 



0.024 



0.02G 



02 



none 



0.028 

 0.02 



0.006 



0.006 

 0.002 



trace 



0.004 

 0.004 



NO2 



0.00018 



0.00018 



0.00016 



0.0002 



0.00026 



0.0002 



0.0001 



none 



0.00006 



0.00004 

 0.00000 



none 



0.00004 

 0.00008 



Total N. 



0.88 



0:50 



the southerly slopes of Mt. Martin and Mt. Mageik. This 

 area was to the windward of the Volcano at the time of the 

 eruption and consequently received but a slight fall of ash and 

 pumice. The pre-eruptive vegetation along its head-waters still 

 persists, and the frequent floods coming down throughout the 

 summer might be expected to scatter this vegetation far and 

 wide over the everchanging ash and pumice bars of the lower 

 Katmai Valley. Just below the junction of Martin Creek 

 with Katmai River lies an extensive flat covered by river 



