36 ROYAL SOCIETY OF CANADA 
were all freshly fallen snow, care being exercised to collect either during 
the snow fall or within a few hours of its cessation. The snow was 
allowed to melt at room temperatures (about 70°F), in a clean, covered 
glass vessel. Not one of the samples, as taken, appeared in the slighest 
degree dirty or soiled, all to the eye at the time of the collection were of 
the purest whiteness, nevertheless on melting there was on the surface of 
the resulting water or clinging to the sides of the vessel a certain amount 
of sooty material and frequently also there was a slight deposit. 
The determinations made comprised nitrogen present as free am- 
monia, albuminoid ammonia, and nitrates and nitrites. 
The tabulated data are as follows: 





NITROGEN. 
Date of Collection. Parts per million, 
1907. 
As Free As Albd. As Nitrates and 
Ammonia. Ammonia. Nitrites. 
February, 2lst 0er” .243 .045 .136 
sy 26) 0 0 ARS M RSR Ce .276 .078 .300 
March r4 thy RE Re eme .161 .044 .170 
‘Ath, (12 hours after pre- 
ceding) ..... 171 .047 .170 
LA 057) 0 Merk Seth calcite PL À .412 .045 .390 
AE AD EN ANR RNE EN ER ARE .284 .058 .128 
Seoul NS TEE 18 AAG ASIA: .095 .049 11 
April MEL EE oser ele .140 -058 024 
SC ONO bln Usain endear EEE . 255 058 .107 
CA LAC) ss PE .589 .066 .317 
COMO € AN EE A AN ARRET RENNES .360 .041 .033 
May Ath} NAME Ra et .082 .033 .065 
AVE RAGE Sem A means ture .256 | 052 .163 



Total nitrogen (average) — .471 part per million. 
From the wide fluctuations noticeable in the nitrogen content of 
these samples it is evident that the condition of the atmosphere of a 
locality may change both frequently and considerably, though it may also 
be supposed that the size of the flakes and the temperature of the atmos- 
phere during the fall exert an influence on the filtering and solvent 
powers of the snow. The writer thought it quite probable that when 
