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THE ROYAL SOCIETY OF CANADA 



the nitrogen furnished to the soil is from that source ; in five years of the 

 seven this proportion has been very close to 85 per cent. 



Amounts of Nitrogen Furnished by Rain and Snow. 



Considering the distribution or proportion of the various nitrogen 

 compounds, it has been found that, of the total nitrogen, approximately 

 70 per cent is present as free and organic ammonia and 30 per cent 

 as nitrates. This is illustrated by the data for the year 1913-14 

 given in the following table, which also allows a comparison of the 

 composition of rain and snow. Though as regards the proportions 

 of the several compounds, present in rain and snow, the differences 

 between these two forms of precipitation are not large, the greater 

 richness of rain in all three forms is apparent. 



Average Nitrogen-Content of Rain and Snow. 



(Amount of Nitrogen per Acre as Free and Albuminoid Ammonia and as Nitrates 

 and Nitrites.) 



An interesting phase of the subject is the study of the various 

 factors that influence the nitrogen content of the precipitation, and 

 especially that of the rain. Mention has been made of one of the most 

 notable of these — a smoke-laden atmosphere due to bush fires. These 



* Snowfall exceptionally heavy. 

 ** Rain abnormally rich in ammonia due to bush fires. 



