NITROGEN IN RAIN AND SNOW. 



BY NICHOLAS KNIGHT, 



Shutt, Chemical News, December 10, 1909, determined the nitrogen 

 in the rain and snow that fell near Ottawa, Canada, during a portion of 

 the year 1906 and 1907. It occurred to us it might be interesting and 

 profitable to study the precipitations of Mount Vernon, Iowa. .The in- 

 vestigation was begun on January 12, 1910, and was continued for one 

 year with the exception of the months of May, June, July and August. 

 These were extremely dry months and we regret very much not to have 

 been able to secure a sample of the heavy rainfall which broke the long 

 drought, during the latter part of August. 



There were in all seventeen samples collected, nine of snow and eight 

 of rain. A foot of snow was upon the ground from which the first 

 sample was taken. With this exception samples were collected during 

 the precipitation. 



Both rain and snow were collected in a large pan, twenty inches in 

 diameter, either upon the top of a college building or upon the ground on 

 the open campus. Concordant results were obtained from both localities. 

 The college is located upon a hill southwest of the village of seventeen 

 hundred inhabitants. The samples were thus considered quite free from 

 contamination. We computed the weight of one inch of rainfall upon an 

 acre to be 226,875 pounds. Then, if the rainfall should be one inch, 

 and should contain .02 free ammonia per million, the weight multiplied 

 by .02 and the product by 14-17 would express the nitrogen in pounds. 



The nitrogen exists in free ammonia, albuminoid ammonia, nitrates 

 and nitrites. The nitrogen in the two last was not determined separate- 

 ly, but together. It was reduced to ammonia with nascent hydrogen 

 and the amount of ammonia obtained was also multiplied by the frac- 

 tion 14-17. We found the least amount of nitrogen in the albuminoid 

 ,'immonia, the most in the nitrates and nitrites, and in the free ammonia 

 between the two. The nitrogen in the nitrites and nitrates is the most 

 available form for plant food and the amount is doubtless dependent on 

 the frequency and duration of thunderstorms. 



