76 IOWA ACADEMY OF SCIENCE 



The snowfall during the period mentioned was 41.75 inches, equiva- 

 lent to 4.17 inches of rain, and the rainfall was 2.64 inches. The free 

 ammonia averages 1.52 parts and the albuminoid ammonia 1.17 parts 

 per million for the snow. The free ammonia is 3.08 parts and the al- 

 buminoid ammonia 1.25 parts per million in the rain. Thus it is seen 

 that the free ammonia is greater in rain than in snow, while the albumi- 

 noid ammonia is approximately the same in both. In the nitrites and 

 nitrates we found the average in the rain to be 3.45 parts per million 

 and 6.04 parts per million in the snow. This suggests the value of heavy 

 snows to the soil in supplying it with plant food. Another interesting 

 fact is the large amount of free ammonia in the rain of April 5 which 

 was 13.3 parts per million. This is no doubt owing to the fact that 

 from February 26th to April 5th there was no precipitation. The rain 

 continuing the following day, there were only two parts per million. 

 It was found that the amount of nitrogen in the various compounds 

 varied directly with the lapse of time between the precipitations. The 

 question might arise in regard to the amount of nitrogen which may be 

 deposited in the dew. The total number of pounds of nitrogen per acre 

 as shown in Table II is 13.7132. The amount would probably vary 

 greatly in different localities, and in the different seasons. The entire 

 precipitation from January 1st to June 10th was equivalent to 6.81 

 inches of rain. This was very light for the period covered. A normal 

 precipitation for this section is 10 to 15 inches. 



Date Rain 



January 1-12 



January 13 



January 26 



Fetiruary 20 



February 22 



February 26 25 



March 



April 5 1 



April 6 5 



April 15 25 



April 16 



April 22 25 



April 23 12 



September 22 5 



October 20 75 



November 4 



December 2 



December 9 



