19141 
NOLTE—SALIVARY ORGANISMS AND AIR POLLUTION 71 
pends, of course, on the amount of coughing, sneezing, speaking, 
etc., of its occupants. А саг may be very crowded but if no 
coughing, etc., is going on, there will, theoretically, be no pollu- 
tion of the atmosphere from saliva. Again, if there is much 
talking, etc., among those present, the atmosphere may be 
greatly polluted by the dissemination of particles of saliva from 
the mouth. 
The samples were always taken in the early morning between 
the hours of six and seven, when the majority of the laboring 
class are on their way to work. "The tendency of the passengers 
at this time of the day is to be quiet, as the morning paper is of 
absorbing interest to a majority. Тһе samples of air were taken 
in the center of the car, the opening of the apparatus being about 
4 feet from the floor level. In these experiments the apparatus 
described above was used. In all cases 10,800 cc. of air were 
drawn through the sand filter at the rate of 900 cc. per minute. 
The sand was introduced into 15 се. of sterile distilled water 
and plated as shown in table тх. 
The experiments carried out in street cars will now be taken 
up in order and the results discussed. If it can be shown that 
the characteristic salivary organism is present in the air of these 
cars in sufficient quantity, and if it can later be proved that this 
salivary organism is not present in the open air, it follows that 
the atmosphere in these cars is being polluted by the dissemina- 
tion of particles of saliva from the mouth. 
Experiment 3.—While the air sample was being taken for this 
experiment, 44 people were seated in the car, but none were 
standing. Out of the 20 colonies appearing on the plate (see 
table тх), 9 were of bacilli and 11 of coccus forms. Inoculated 
into the 3 differential media, 8 of the latter reacted negatively 
in all three media, 1 negatively on lactose and milk, but posi- 
tively on saccharose, and 2 gave positive reactions in all three 
media. 
It will be recalled that mention has been made of several 
organisms, both among the salivary and air cocci, which gave а 
positive reaction with saccharose, but reacted negatively with 
lactose and milk. 'The one above referred to as reacting in 
this manner is probably one of these unidentified coccus 
forms which seem to be present in both saliva and air. Out of 
