1914] 
NOLTE—SALIVARY ORGANISMS AND AIR POLLUTION 15 
in the midst of a crowd of about 100 people in front of a counter. 
On the plate examined, a total of 36 colonies developed—16 
bacillus and 20 coccus. Of the latter, 18 gave negative reactions 
throughout on the three differential media, and 2 reacted nega- 
tively on saccharose and milk but positively on lactose, the 
latter sugar being fermented. No salivary coccus forms were 
isolated, indicating that the air in the basement at the time of 
the experiment was ''safe." 
Experiment 7.—This air sample was taken under practically 
the same conditions as in the previous experiment except that 
only about 50 people were in the crowd. The plate examined 
contained 2 streptothrix, 13 bacillus, and 8 coccus colonies. АП 
of the cocci gave negative reactions throughout on the three 
differential media. Хо salivary coccus forms were found, which 
fact leads again to the conclusion that the sanitary quality of 
the air during the experiment was ''safe." 
EXPERIMENTS 2, 12, 13, 14 
These experiments were performed outdoors. Тһе air sample 
for experiment 2 was collected in a railroad switch yard at a time 
when there was no traffic. Тһе samples for experiments 12, 13, 
and 14 were collected in the immediate vicinity of large storage 
basins belonging to the local water works and located 300 or 400 
feet from the bank of the Mississippi River. Тһе apparatus 
used was the same as that employed in the previous experi- 
ments. 
Experiment 2.—The outdoor temperature was 29?F., and 
while the air sample was being taken it was snowing. A total 
of 22,500 се. of air was drawn through the sand filter at the rate 
of 750 се. per minute—the operation extending over a period of 
30 minutes. Samples were plated as shown in table Іх. Of 
the 3 plates examined, plate 1 yielded 2 bacillus colonies; plate 
2, 1 streptothrix, 1 bacillus, and 6 coccus colonies; and plate 4, 
2 mold, 1 streptothrix, 1 bacillus, and 2 coccus colonies. All 
of the coccus forms were grown on the three differential media, 
7 giving negative reactions throughout, while 1 reacted positively 
on saccharose and negatively on lactose and milk. Тһе latter 
organism is one of the unidentified coccus forms previously 
referred to. Хо characteristic salivary cocci were found, in- 
