102 
PROF. T. CARNELLEY, MR. J. S. HALDANE, AND DR. A. M. ANDERSON 
The air of a dwelling;-house or school must be considered bad if the following- 
o O 
limits be exceeded :—* 
-i . ■ t f For dwelling-houses 
Oarbomc acid < ^ , n ° 
(_ 4 or schools 
Organic matter. 
Total micro-organisms. 
Total. 
Excess over outside air. 
10 vols. per 10,000 
13 ,, ,, 
6 vols. per 10,000 
9 
2'0 vols. oxygen per 1,000,000 
20 per litre 
The ratio 
Bacteria 
Moulds 
should not exceed 30. 
* The above standards are based on the following data:— 
Carbonic Acid— 
Of the 29 one-roomed houses examined, 14 contained above and 15 below 10 vols. (total), 
or 9 above and 16 below 6 vols. (excess). 
Of the 13 two-roomed houses examined, 5 contained above and 7 below 10 vols. (total), 
or 8 above and 3 below 6 vols. (excess). 
Of the 18 four (and more) -roomed houses examined, 1 contained above and 17 below 10 vols. (total), 
or 1 above and 17 below 6 vols. (excess). 
Of the 42 naturally ventilated school-rooms examined, 38 contained above and 4 below- 10 vols. (total), 
or 41 above and 1 below 6 vols. (excess). 
Of the 26 mechanically ventilated school-rooms examined, 21 contained above and 5 below 10 vols. 
(total), or 18 above and 8 below 6 vols. (excess). 
Of the 42 naturally ventilated school-rooms examined, 31 contained above and 11 below 13 vols. 
(total), or 31 above and 11 below 9 vols. (excess). 
Of the 26 mechanically ventilated school-rooms examined, 9 contained above and 17 below 13 vols. 
(total), or 8 above and 18 below 9 vols. (excess). 
Of the 42 natui-ally ventilated school-rooms examined, 29 contained above and 13 below 14 vols. 
(total). 
Of the 26 mechanically ventilated school-rooms examined, 4 contained above and 22 below 14 vols. 
(total). 
Organic Matter (excess over outside air)— 
Of 29 one-roomed houses, 25 required more and 4 less than 2 vols. oxygen per million. 
Of 11 two-roomed houses, 7 required more and 4 le£s than 2 vols. oxygen per million. 
Of 13 four (and more) -roomed houses, 2 required more and 11 less than 2 vols. oxygen per million. 
Of 41 natui-ally ventilated school-rooms, 35 required more and 6 less than 2 vols. oxygen per million. 
Of 26 mechanically ventilated school-rooms, 5 required more and 21 less than 2 vols. oxygen per 
million. 
Micro-organisms (excess over outside air)— 
Of 28 one-roomed houses, 22 contained more and 6 less than 20 micro-organisms per litre. 
Of 13 two-roomed houses, 9 contained more and 4 less than 20 micro-organisms per litre. 
Of 18 four (and more) -roomed houses, 1 contained more and 17 less than 20 micro-organisms per litre. 
Of 38 naturally ventilated school-rooms, 32 contained more and 6 less than 20 micro-organisms per 
litre. 
Of 25 naturally ventilated school-rooms, 6 contained more and 19 less than 20 micro-organisms per 
litre. 
