272 Proceedings of Indiana Academy of Ncience. 
ozone should be so low that the ordinary person does not notice its presence 
on entering the room where it is used. Most of the cabinet forms of 
ozonizers have had perhaps ten times too great a capacity. 
There are certain places where it would be very desirable to have better 
air. The crowded office and school room, the well attended movie theater 
and church, or the basements of the large department stores, all have 
trouble in securing proper ventilation. There seem to be exhaled from the 
human body certain substances which tend to make the air feel “close” 
and after they have been breathed a little while a person becomes drowsy 
and feels uncomfortable. To provide fresh air the atmosphere in a crowded 
room has to be renewed sometimes as many as eight times in an hour. 
In the cold weather this means that a lot of coal is required to warm up 
all of this air which does not remain behind very long before it is dis- 
carded. If some means could be provided for removing the deleterious 
substances from this air allowing it to be recirculated there would be a 
great saving in coal. The question then arises as to whether ozone will 
accomplish this desirable result. About this question there has been waged 
quite a little controversy pro and con. Emphatic statements have been made 
on both sides so that it is somewhat difficult to decide just what the truth 
of the matter is and a careful survey of the literature does not settle the 
question either way, for there are not sufficient results of decisive experi- 
ments to allow one to decide. Until the question has been cleared up by 
high class experimental work, which will analyze the problem into its differ- 
ent factors, we shall have to fall back upon certain positive results which 
have been actually obtained in practice. 
In St. Louis, and the same thing must hold true here in Indianapolis, the 
school rooms where colored children or the children of the ‘‘great unwashed” 
portion of the population gather are rather hard to ventilate. In St. Louis 
a number of the teachers in such schools were complaining of ill health and 
great discomfort from the inadequate ventilation. The children too, would 
become drowsy and the school work did not go forward as it should. When 
some of the teachers threatened to resign the problem was put up to Mr. 
Hallett, the chief engineer of the school board. He recommended the use of 
ozone and had it installed in two of the worst schools. After that complaints 
ceased and a questioniare sent out to the teachers found them enthusiastic 
about the new system. Not only were they relieved from the almost 
nauseating bad odors but the children were also taking an interest in their 
work which they had not shown previously. The experiment has been so 
successful that the use of ozone has been extended to many other school 
buildings in that city and when a new building is put up an ozone system is 
always included. 
Economically, the big advantage of the system is that the air can be 
recirculated so that a large part of the heat is saved. The writer visited 
a school in the city of St. Louis where air was recirculated with the aid of 
ozone. The odor of ozone was barely perceptible so that it was not at all 
disagreeable. The children were not at all drowsy as they so often are in 
the middle of the afternoon, but were very wide awake. The teachers on 
being questioned, all were quite enthusiastic about the ventilation, and one 
dear old frail lady said that she had not lost a day since the introduction 
of ozone, whereas before she had lost a great deal of time. 
