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ROYAL SOCIETY OF CANADA 



since the previous precipitation, though the amount of rain or snow fall- 

 ing, naturally, detennines to some degree the composition in this regard. 

 OnjB or two examples to illustrate these points may be taken from the 

 year's record. Between the ISth and 26th of June there had been no 

 rain. On the morning of the 26th 0.05 inches rain fell and again in 

 the evening of the same day, 0.16 inch. The analytical data are as 

 follows ; 



Again in July, after a period of three days without rain, similar 

 results were obtained. 



From the smaller percentage of nitrogen compounds in snow, to 

 which we have already referred, it might be conjectured that the solvent 

 or absorbent action of snow was less than that of rain, and this appears 

 to be the case. Thus, snow fell to a depth of 8-75 inches during the 

 early hours of December 30th, which on analysis was found to contain 

 0.09 p.p.m. nitrogen as free ammonia, 0.086 p.p.m. as albuminoid 

 ammonia and 0.115 p.p.m. as nitrates and nitritee, a total of 0.291 

 p.p.m. of snow water. Later in the day, about 10-30 A.M., the tem- 

 perature rose slightly anid the snow turned to a light rain, of which a 

 precipitation of .15 inch was recorded. Upon analysis this rain water 



