82 
PROF. T. CARNELLEY, MR. J. S. HALDANE, AND DR. A. M. ANDERSON 
need not be surprised at the unhealthy appearance of very many of these children. 
It must also be borne in mind that many of them are exposed for nine hours more to 
an atmosphere which, as we have shown above, is about five tunes as impure as that 
of an ordinary bed-room in a middle-class house. They are thus breathing for at least 
fifteen hours out of the twenty-four a highly impure atmosphere. The effects of this 
are often intensified, as is well known, by insufficient food and clothing, both of which 
must render them less capable of resisting the impure air. The fact that these schools 
become, as will be shown below, after a time habitually infected by bacteria renders it 
probable that they also become permanent foci of infection for various diseases, and 
particularly perhaps for tubercular disease in its various forms. From the considera¬ 
tions advanced later on (page 106), it will be seen how an ordinary simple cold, 
brought on say by a draught, may become a source of great danger to a child attending 
such a school. 
The cubic space per person in schools, unlike that in houses, shows no definite con¬ 
nexion (as will be seen below) with the purity of the air, except as regards the 
number of micro-organisms. In mechanically ventilated schools these dimini sh in a 
marked manner with increase of cubic space. In naturally ventilated schools, on the 
other hand, the number of micro-organisms was found to increase as the cubic space 
increases from 50 to 250 cubic feet, after which it diminished (cf. pp. 93, 94, 95). 
Naturally ventilated. 
Mechanically ventilated. 
Cubic space per person. 
No. of 
cases. 
Carbonic 
Acid. 
Organic 
matter. 
Total 
micro¬ 
organisms. 
No. of 
cases. 
Carbonic 
Acid. 
Organic 
matter. 
Total 
micro¬ 
organisms. 
Cubic feet. 
50-100 
6 
21-5 
16-2 
119 
100-150 
14 
15-5 
19-6 
128 
7 
14-0 
7-8 
23 
150-200 
5 
18-9 
123 
150 
8 
11-4 
9-6 
14 
200-250 
9 
21-1 
16-8 
188 
5 
11-8 
12-3 
10 
250-300 
4 
17-1 
9 - 5 
187 
300 and upwards 
4 
15-1 
11-8 
12 
6 
13-0 
3-7 
2 
Boys’ and Girls School-rooms .—The difference between boys’ and girls’ rooms is most 
marked. Out of fifteen pairs of rooms, one room of each pah- being occupied by boys 
and the other by girls, and under circumstances* as nearly as possible the same, no less 
than fourteen gave a much lower result in favour of the girls as regards micro¬ 
organisms, whilst the only exception against the girls was a room in one of the 
denominational schools. This room was lighted only by two skylights, though in 
* Such as class of children, mode of ventilating, cubic space, time of experiment, &c., and, with but 
one exception, in the same building; iu this exception the two schools were in connexion with one 
another. 
